diff --git a/.gitignore b/.gitignore
index 3b569a93..9ad73290 100644
--- a/.gitignore
+++ b/.gitignore
@@ -2,6 +2,7 @@
 *.log
 node_modules
 !test/fixtures/errors/bad-gulp-version/node_modules/
+!test/fixtures/config/theming/error/badGulpVersion/node_modules/
 build
 *.node
 components
diff --git a/index.js b/index.js
index 1f928acb..e2683894 100644
--- a/index.js
+++ b/index.js
@@ -21,7 +21,7 @@ var theme = require('./lib/shared/log/theme');
 var msgs = require('./lib/shared/log/messages');
 
 var mergeProjectAndUserHomeConfigs = require('./lib/shared/config/merge-configs');
-var overrideEnvFlagsByConfigAndCliOpts = require('./lib/shared/config/env-flags');
+var overrideEnvByConfigAndCliOpts = require('./lib/shared/config/env-config');
 
 // Get supported ranges
 var ranges = fs.readdirSync(path.join(__dirname, '/lib/versioned/'));
@@ -100,7 +100,7 @@ module.exports = run;
 
 function onPrepare(env) {
   var cfg = mergeProjectAndUserHomeConfigs(env);
-  env = overrideEnvFlagsByConfigAndCliOpts(env, cfg, opts);
+  env = overrideEnvByConfigAndCliOpts(env, cfg, opts);
 
   // Set up event listeners for logging again after configuring.
   toConsole(log, env.config.flags);
@@ -131,7 +131,6 @@ function onExecute(env) {
   }
 
   if (!env.modulePath) {
-    /* istanbul ignore next */
     var missingNodeModules =
       fs.existsSync(path.join(env.cwd, 'package.json'))
       && !fs.existsSync(path.join(env.cwd, 'node_modules'));
@@ -139,7 +138,6 @@ function onExecute(env) {
     var hasYarn = fs.existsSync(path.join(env.cwd, 'yarn.lock'));
     var hasNpm = !hasYarn;
 
-    /* istanbul ignore if */
     if (missingNodeModules) {
       log.error(msgs.error.nodeModulesNotFound, tildify(env.cwd), hasYarn, hasNpm);
     } else {
diff --git a/lib/shared/config/env-flags.js b/lib/shared/config/env-config.js
similarity index 78%
rename from lib/shared/config/env-flags.js
rename to lib/shared/config/env-config.js
index 59b4d4be..4fc34e54 100644
--- a/lib/shared/config/env-flags.js
+++ b/lib/shared/config/env-config.js
@@ -5,6 +5,9 @@ var copyProps = require('copy-props');
 
 var mergeCliOpts = require('./cli-flags');
 
+var theme = require('../log/theme');
+var msgs = require('../log/messages');
+
 var toEnvFromConfig = {
   configPath: 'flags.gulpfile',
   configBase: 'flags.gulpfile',
@@ -12,7 +15,7 @@ var toEnvFromConfig = {
   nodeFlags: 'flags.nodeFlags',
 };
 
-function overrideEnvFlags(env, config, cliOpts) {
+function overrideEnvConfig(env, config, cliOpts) {
   cliOpts = mergeCliOpts(cliOpts, config);
 
   // This must reverse because `flags.gulpfile` determines 2 different properties
@@ -21,10 +24,18 @@ function overrideEnvFlags(env, config, cliOpts) {
 
   env.config = {
     flags: cliOpts,
+    theme: theme,
+    msgs: msgs,
   };
   if (config.description) {
     env.config.description = config.description;
   }
+  if (config.theme) {
+    copyProps(config.theme, env.config.theme);
+  }
+  if (config.msgs) {
+    copyProps(config.msgs, env.config.msgs);
+  }
   return env
 
   function convert(configInfo, envInfo) {
@@ -53,4 +64,4 @@ function overrideEnvFlags(env, config, cliOpts) {
   }
 }
 
-module.exports = overrideEnvFlags;
+module.exports = overrideEnvConfig;
diff --git a/lib/shared/config/merge-configs.js b/lib/shared/config/merge-configs.js
index 8202f182..e3c17a81 100644
--- a/lib/shared/config/merge-configs.js
+++ b/lib/shared/config/merge-configs.js
@@ -5,6 +5,7 @@ var path = require('path');
 
 function mergeConfigs(env) {
   var cfg = {};
+  /* istanbul ignore if */
   if (env.configFiles.userHome) {
     copyConfig(env.config.userHome, cfg, env.configFiles.userHome);
   }
diff --git a/lib/shared/log/messages.js b/lib/shared/log/messages.js
index 642f94aa..c4f5937f 100644
--- a/lib/shared/log/messages.js
+++ b/lib/shared/log/messages.js
@@ -158,7 +158,7 @@ module.exports = {
       '{IF:{3:has cause}?\n{TIMESTAMP}{ERROR: {4:cause}}}',
 
     taskNotFound:
-      '{TIMESTAMP}{ERROR: Task never defined: {1:task}}\n' +
+      '{TIMESTAMP}{ERROR: Task never defined: {1:target task}{IF:{2:has similar tasks}? - did you mean? {3:similar tasks}}\n' +
       '{TIMESTAMP}{ERROR: To list available tasks, try running: gulp --tasks}',
 
     failToRun:
diff --git a/lib/shared/log/tasks.js b/lib/shared/log/tasks.js
index 1a6db4ed..b84791ed 100644
--- a/lib/shared/log/tasks.js
+++ b/lib/shared/log/tasks.js
@@ -15,7 +15,7 @@ function logTasks(tree, opts, getTask) {
   var maxDepth = opts.tasksDepth;
   if (typeof maxDepth !== 'number') {
     maxDepth = 50;
-  } else if (maxDepth < 1) {
+  } else /* istanbul ignore if */ if (maxDepth < 1) {
     maxDepth = 1;
   }
 
@@ -38,7 +38,7 @@ function printTaskTree(tree, opts) {
   tree.nodes.forEach(function(node, idx, arr) {
     var isLast = idx === arr.length - 1;
     var w = createTreeLines(node, lines, opts, 1, '', isLast);
-    maxLabelWidth = Math.max(maxLabelWidth, w || 0);
+    maxLabelWidth = Math.max(maxLabelWidth, w || /* istanbul ignore next */ 0);
   });
 
   lines.forEach(function(line) {
diff --git a/lib/shared/log/timestamp.js b/lib/shared/log/timestamp.js
index 99c71d46..4e9dd9a6 100644
--- a/lib/shared/log/timestamp.js
+++ b/lib/shared/log/timestamp.js
@@ -1,6 +1,7 @@
 'use strict';
 
 function timestamp(format) {
+  /* istanbul ignore if */
   if (typeof format !== 'string') {
     return noop;
   }
@@ -42,6 +43,7 @@ function timestamp(format) {
   return result;
 }
 
+/* istanbul ignore next */
 function noop() {
   return "";
 }
diff --git a/lib/shared/log/to-console.js b/lib/shared/log/to-console.js
index 9bcf3335..844343aa 100644
--- a/lib/shared/log/to-console.js
+++ b/lib/shared/log/to-console.js
@@ -16,11 +16,12 @@ var levels = [
 ];
 
 function consoleLog(s) {
-  if (s != null) console.log(s);
+  if (s) console.log(s);
 }
 
 function consoleError(s) {
-  if (s != null) console.error(s);
+  /* istanbul ignore else */
+  if (s) console.error(s);
 }
 
 function cleanup(log) {
diff --git a/lib/versioned/^3.7.0/index.js b/lib/versioned/^3.7.0/index.js
index 7da49d19..77c45b87 100644
--- a/lib/versioned/^3.7.0/index.js
+++ b/lib/versioned/^3.7.0/index.js
@@ -54,14 +54,14 @@ function execute(env) {
     }
     if (opts.tasks) {
       tree = taskTree(gulpInst.tasks);
-      tree.label = getTasksDescription(env);
+      tree.label = getTasksDescription(env, true);
       return logTasks(tree, opts, function(task) {
         return gulpInst.tasks[task].fn;
       });
     }
     if (opts.tasksJson) {
       tree = taskTree(gulpInst.tasks);
-      tree.label = getTasksDescription(env);
+      tree.label = getTasksDescription(env, false);
 
       var output = JSON.stringify(copyTree(tree, opts));
 
diff --git a/lib/versioned/^3.7.0/log/tasks-description.js b/lib/versioned/^3.7.0/log/tasks-description.js
index 031ff59e..fe19e397 100644
--- a/lib/versioned/^3.7.0/log/tasks-description.js
+++ b/lib/versioned/^3.7.0/log/tasks-description.js
@@ -5,14 +5,22 @@ var tildify = require('../../../shared/tildify');
 var theme = require('../../../shared/log/theme');
 var msgs = require('../../../shared/log/messages');
 
-function getTasksDescription(env) {
+function getTasksDescription(env, isBackslashEscaping) {
   var desc;
   if (env.config.description && typeof env.config.description === 'string') {
     desc = env.config.description;
   } else {
     desc = msgs.tasks.gulpfile;
   }
-  return format(theme, desc, tildify(env.configPath));
+  var gulpfile = tildify(env.configPath);
+  if (isBackslashEscaping) {
+    gulpfile = escapeBackslash(gulpfile);
+  }
+  return format(theme, desc, gulpfile);
+}
+
+function escapeBackslash(s) {
+  return s.replace(/\\/g, '\\\\');
 }
 
 module.exports = getTasksDescription;
diff --git a/lib/versioned/^4.0.0-alpha.1/index.js b/lib/versioned/^4.0.0-alpha.1/index.js
index 845a1b85..06d700e0 100644
--- a/lib/versioned/^4.0.0-alpha.1/index.js
+++ b/lib/versioned/^4.0.0-alpha.1/index.js
@@ -55,7 +55,7 @@ function execute(env) {
     }
     if (opts.tasks) {
       tree = {};
-      tree.label = getTasksDescription(env);
+      tree.label = getTasksDescription(env, true);
       tree.nodes = gulpInst.tree({ deep: true });
 
       return logTasks(tree, opts, function(taskname) {
@@ -64,7 +64,7 @@ function execute(env) {
     }
     if (opts.tasksJson) {
       tree = {};
-      tree.label = getTasksDescription(env);
+      tree.label = getTasksDescription(env, false);
       tree.nodes = gulpInst.tree({ deep: true });
 
       var output = JSON.stringify(copyTree(tree, opts));
@@ -82,9 +82,9 @@ function execute(env) {
         }
       });
     } catch (err) {
-      var taskName = checkTaskNotFound(err);
-      if (taskName) {
-        log.error(msgs.error.taskNotFound, taskName);
+      var task = checkTaskNotFound(err);
+      if (task) {
+        log.error(msgs.error.taskNotFound, task.target, Boolean(task.similar), task.similar);
       } else {
         log.error(msgs.error.failToRun, err.message);
       }
diff --git a/lib/versioned/^4.0.0-alpha.2/index.js b/lib/versioned/^4.0.0-alpha.2/index.js
index 058559ae..23a75047 100644
--- a/lib/versioned/^4.0.0-alpha.2/index.js
+++ b/lib/versioned/^4.0.0-alpha.2/index.js
@@ -57,12 +57,12 @@ function execute(env) {
     }
     if (opts.tasks) {
       tree = gulpInst.tree({ deep: true });
-      tree.label = getTasksDescription(env);
+      tree.label = getTasksDescription(env, true);
       return logTasks(tree, opts, getTask(gulpInst));
     }
     if (opts.tasksJson) {
       tree = gulpInst.tree({ deep: true });
-      tree.label = getTasksDescription(env);
+      tree.label = getTasksDescription(env, false);
 
       var output = JSON.stringify(copyTree(tree, opts));
 
@@ -80,9 +80,9 @@ function execute(env) {
         }
       });
     } catch (err) {
-      var taskName = checkTaskNotFound(err);
-      if (taskName) {
-        log.error(msgs.error.taskNotFound, taskName);
+      var task = checkTaskNotFound(err);
+      if (task) {
+        log.error(msgs.error.taskNotFound, task.target, Boolean(task.similar), task.similar);
       } else {
         log.error(msgs.error.failToRun, err.message);
       }
diff --git a/lib/versioned/^4.0.0/index.js b/lib/versioned/^4.0.0/index.js
index a46a8cef..cedd4290 100644
--- a/lib/versioned/^4.0.0/index.js
+++ b/lib/versioned/^4.0.0/index.js
@@ -57,12 +57,12 @@ function execute(env) {
     }
     if (opts.tasks) {
       tree = gulpInst.tree({ deep: true });
-      tree.label = getTasksDescription(env);
+      tree.label = getTasksDescription(env, true);
       return logTasks(tree, opts, getTask(gulpInst));
     }
     if (opts.tasksJson) {
       tree = gulpInst.tree({ deep: true });
-      tree.label = getTasksDescription(env);
+      tree.label = getTasksDescription(env, false);
 
       var output = JSON.stringify(copyTree(tree, opts));
 
@@ -80,9 +80,9 @@ function execute(env) {
         }
       });
     } catch (err) {
-      var taskName = checkTaskNotFound(err);
-      if (taskName) {
-        log.error(msgs.error.taskNotFound, taskName);
+      var task = checkTaskNotFound(err);
+      if (task) {
+        log.error(msgs.error.taskNotFound, task.target, Boolean(task.similar), task.similar);
       } else {
         log.error(msgs.error.failToRun, err.message);
       }
diff --git a/lib/versioned/^4.0.0/log/check-task-not-found.js b/lib/versioned/^4.0.0/log/check-task-not-found.js
index fb45d7fd..e996f212 100644
--- a/lib/versioned/^4.0.0/log/check-task-not-found.js
+++ b/lib/versioned/^4.0.0/log/check-task-not-found.js
@@ -1,10 +1,24 @@
 'use strict';
 
 function checkTaskNotFound(err) {
-  var result = /^Task never defined: +(.*)$/.exec(err.message);
-  /* istanbul ignore else */
-  if (result) {
-    return result[1];
+  /* istanbul ignore if */
+  if (!err || !err.message) {
+    return undefined;
+  }
+  var fixed0 = 'Task never defined: ';
+  var fixed1 = ' - did you mean? ';
+
+  if (err.message.startsWith(fixed0)) {
+    var target = err.message.slice(fixed0.length);
+    var similar = undefined;
+
+    var index = target.indexOf(fixed1);
+    if (index >= 0) {
+      similar = target.slice(index + fixed1.length);
+      target = target.slice(0, index);
+    }
+
+    return { target: target, similar: similar };
   }
 }
 
diff --git a/lib/versioned/^4.0.0/log/tasks-description.js b/lib/versioned/^4.0.0/log/tasks-description.js
index 031ff59e..fe19e397 100644
--- a/lib/versioned/^4.0.0/log/tasks-description.js
+++ b/lib/versioned/^4.0.0/log/tasks-description.js
@@ -5,14 +5,22 @@ var tildify = require('../../../shared/tildify');
 var theme = require('../../../shared/log/theme');
 var msgs = require('../../../shared/log/messages');
 
-function getTasksDescription(env) {
+function getTasksDescription(env, isBackslashEscaping) {
   var desc;
   if (env.config.description && typeof env.config.description === 'string') {
     desc = env.config.description;
   } else {
     desc = msgs.tasks.gulpfile;
   }
-  return format(theme, desc, tildify(env.configPath));
+  var gulpfile = tildify(env.configPath);
+  if (isBackslashEscaping) {
+    gulpfile = escapeBackslash(gulpfile);
+  }
+  return format(theme, desc, gulpfile);
+}
+
+function escapeBackslash(s) {
+  return s.replace(/\\/g, '\\\\');
 }
 
 module.exports = getTasksDescription;
diff --git a/test/config-theme-and-msgs.js b/test/config-theme-and-msgs.js
new file mode 100644
index 00000000..89032891
--- /dev/null
+++ b/test/config-theme-and-msgs.js
@@ -0,0 +1,561 @@
+'use strict';
+
+var expect = require('expect');
+var exec = require('child_process').exec;
+var path = require('path');
+var fs = require('fs');
+var os = require('os');
+
+var tildify = require('../lib/shared/tildify');
+
+var baseDir = path.join(__dirname, 'fixtures/config/theming');
+var expectedDir = path.join(__dirname, 'expected/config/theming');
+
+var eraseTime = require('./tool/erase-time');
+var eraseLapse = require('./tool/erase-lapse');
+var gulp = require('./tool/gulp-cmd');
+
+describe('config: theme.* & msgs.*', function() {
+
+  it('Should change help.usage with .gulp.*', function(done) {
+    var cwd = path.join(baseDir, 'help/usage');
+    var expected =fs.readFileSync(path.join(expectedDir, 'help/usage/help.txt'), 'utf8');
+
+    var opts = { cwd: cwd };
+    exec(gulp('--help'), opts, cb);
+
+    function cb(err, stdout, stderr) {
+      expect(err).toBeNull();
+      expect(stderr).toEqual('');
+      expect(eraseTime(stdout)).toEqual(expected);
+      done(err);
+    }
+  });
+
+  it('Should change help.flags.* with .gulp.*', function(done) {
+    var cwd = path.join(baseDir, 'help/flags');
+    var expected =fs.readFileSync(path.join(expectedDir, 'help/flags/help.txt'), 'utf8');
+
+    var opts = { cwd: cwd };
+    exec(gulp('--help'), opts, cb);
+
+    function cb(err, stdout, stderr) {
+      expect(err).toBeNull();
+      expect(stderr).toEqual('');
+      expect(eraseTime(stdout)).toEqual(expected);
+      done(err);
+    }
+  });
+
+  it('Should change tasks.gulpfile with .gulp.*', function(done) {
+    var cwd = path.join(baseDir, 'tasks/gulpfile');
+    var gulpfile = tildify(path.join(cwd, 'gulpfile.js'));
+    var expected = '** ' + gulpfile + ' **\n' +
+      '└── default\n';
+
+    var opts = { cwd: cwd };
+    exec(gulp('--tasks'), opts, cb);
+
+    function cb(err, stdout, stderr) {
+      expect(err).toBeNull();
+      expect(stderr).toEqual('');
+      expect(stdout).toEqual(expected);
+      done(err);
+    }
+  });
+
+  it('Should remove task.gulpfile line output with .gulp.*', function(done) {
+    var cwd = path.join(baseDir, 'tasks/gulpfile/remove');
+    var expected = '└── default\n';
+
+    var opts = { cwd: cwd };
+    exec(gulp('--tasks'), opts, cb);
+
+    function cb(err, stdout, stderr) {
+      expect(err).toBeNull();
+      expect(stderr).toEqual('');
+      expect(stdout).toEqual(expected);
+      done(err);
+    }
+  });
+
+  it('Should change tasks.topTask with .gulp.*', function(done) {
+    var cwd = path.join(baseDir, 'tasks/topTask');
+    var gulpfile = tildify(path.join(cwd, 'gulpfile.js'));
+    var expected = 'Tasks for ' + gulpfile + '\n' +
+      '├─┬ **default**  This is default task\n' +
+      '│ │ --ghi        …is a flag for default task\n' +
+      '│ └─┬ <series>\n' +
+      '│   ├── taskA\n' +
+      '│   └── taskB\n' +
+      '├── **taskA**    This is task A\n' +
+      '│   --abc        …is a flag for task A\n' +
+      '└── **taskB**    This is task B\n' +
+      '    --def        …is a flag for task B\n';
+
+    var opts = { cwd: cwd };
+    exec(gulp('--tasks'), opts, cb);
+
+    function cb(err, stdout, stderr) {
+      expect(err).toBeNull();
+      expect(stderr).toEqual('');
+      expect(stdout).toEqual(expected);
+      done(err);
+    }
+  });
+
+  it('Should change tasks.option with .gulp.*', function(done) {
+    var cwd = path.join(baseDir, 'tasks/option');
+    var gulpfile = tildify(path.join(cwd, 'gulpfile.js'));
+    var expected = 'Tasks for ' + gulpfile + '\n' +
+      '├─┬ default    This is default task\n' +
+      '│ │ **--ghi**  » is a flag for default task\n' +
+      '│ └─┬ <series>\n' +
+      '│   ├── taskA\n' +
+      '│   └── taskB\n' +
+      '├── taskA      This is task A\n' +
+      '│   **--abc**  » is a flag for task A\n' +
+      '└── taskB      This is task B\n' +
+      '    **--def**  » is a flag for task B\n';
+
+    var opts = { cwd: cwd };
+    exec(gulp('--tasks'), opts, cb);
+
+    function cb(err, stdout, stderr) {
+      expect(err).toBeNull();
+      expect(stderr).toEqual('');
+      expect(stdout).toEqual(expected);
+      done(err);
+    }
+  });
+
+  it('Should change tasks.childTask with .gulp.*', function(done) {
+    var cwd = path.join(baseDir, 'tasks/childTask');
+    var gulpfile = tildify(path.join(cwd, 'gulpfile.js'));
+    var expected = 'Tasks for ' + gulpfile + '\n' +
+      '├─┬ default  This is default task\n' +
+      '│ │ --ghi    …is a flag for default task\n' +
+      '│ └─┬ **<series>**\n' +
+      '│   ├── **taskA**\n' +
+      '│   └── **taskB**\n' +
+      '├── taskA    This is task A\n' +
+      '│   --abc    …is a flag for task A\n' +
+      '└── taskB    This is task B\n' +
+      '    --def    …is a flag for task B\n';
+
+    var opts = { cwd: cwd };
+    exec(gulp('--tasks'), opts, cb);
+
+    function cb(err, stdout, stderr) {
+      expect(err).toBeNull();
+      expect(stderr).toEqual('');
+      expect(stdout).toEqual(expected);
+      done(err);
+    }
+  });
+
+  it('Should change tasksJson.gulpfile with .gulp.*', function(done) {
+    var cwd = path.join(baseDir, 'tasksJson/gulpfile');
+    var gulpfile = tildify(path.join(cwd, 'gulpfile.js'));
+    var expected = JSON.stringify({
+      label: '** ' + gulpfile + ' **',
+      nodes: [{
+        label: 'default',
+        type: 'task',
+        nodes: [],
+      }],
+    }) + '\n';
+
+    var opts = { cwd: cwd };
+    exec(gulp('--tasks-json'), opts, cb);
+
+    function cb(err, stdout, stderr) {
+      expect(err).toBeNull();
+      expect(stderr).toEqual('');
+      expect(stdout).toEqual(expected);
+      done(err);
+    }
+  });
+
+  it('Should change info.preloadBefore with .gulp.*', function(done) {
+    var cwd = path.join(baseDir, 'info/preloadBefore');
+    var gulpfile = tildify(path.join(cwd, 'gulpfile.js'));
+    var expected = 'PRELOADING **./preload**\n' +
+      'Preloaded external module: ./preload\n' +
+      'Using gulpfile ' + gulpfile + '\n' +
+      'Starting \'default\'...\n' +
+      'Finished \'default\' after ?\n';
+
+    var opts = { cwd: cwd };
+    exec(gulp('--preload ./preload'), opts, cb);
+
+    function cb(err, stdout, stderr) {
+      expect(err).toBeNull();
+      expect(stderr).toEqual('');
+      expect(eraseLapse(eraseTime(stdout))).toEqual(expected);
+      done(err);
+    }
+  });
+
+  it('Should change info.preloadSuccess with .gulp.*', function(done) {
+    var cwd = path.join(baseDir, 'info/preloadSuccess');
+    var gulpfile = tildify(path.join(cwd, 'gulpfile.js'));
+    var expected = 'Preloading external module: ./preload\n' +
+      'PRELOADDED **./preload**\n' +
+      'Using gulpfile ' + gulpfile + '\n' +
+      'Starting \'default\'...\n' +
+      'Finished \'default\' after ?\n';
+
+    var opts = { cwd: cwd };
+    exec(gulp('--preload ./preload'), opts, cb);
+
+    function cb(err, stdout, stderr) {
+      expect(err).toBeNull();
+      expect(stderr).toEqual('');
+      expect(eraseLapse(eraseTime(stdout))).toEqual(expected);
+      done(err);
+    }
+  });
+
+  it('Should change info.loaderSuccess with .gulp.*', function(done) {
+    this.timeout(0);
+
+    var cwd = path.join(baseDir, 'info/loaderSuccess');
+    var gulpfile = tildify(path.join(cwd, 'gulpfile.babel.js'));
+    var expected = 'LOADED **@babel/register**\n' +
+      'Using gulpfile ' + gulpfile + '\n' +
+      'Starting \'default\'...\n' +
+      'Finished \'default\' after ?\n';
+
+    var opts = { cwd: cwd };
+    exec(gulp('-f gulpfile.babel.js'), opts, cb);
+
+    function cb(err, stdout, stderr) {
+      expect(err).toBeNull();
+      expect(stderr).toEqual('');
+      expect(eraseLapse(eraseTime(stdout))).toEqual(expected);
+      done(err);
+    }
+  });
+
+  it('Should change info.respawn with .gulp.*', function(done) {
+    var cwd = path.join(baseDir, 'info/respawn');
+    var gulpfile = tildify(path.join(cwd, 'gulpfile.js'));
+    var expected = 'RESPAWN BY **--lazy**\n' +
+      'Using gulpfile ' + gulpfile + '\n' +
+      'Starting \'default\'...\n' +
+      'Finished \'default\' after ?\n';
+
+    var opts = { cwd: cwd };
+    exec(gulp('--lazy'), opts, cb);
+
+    function cb(err, stdout, stderr) {
+      expect(err).toBeNull();
+      expect(stderr).toEqual('');
+      expect(eraseLapse(eraseTime(stdout))).toEqual(expected);
+      done(err);
+    }
+  });
+
+  it('Should change info.version with .gulp.*', function(done) {
+    var cwd = path.join(baseDir, 'info/version');
+    var expected = /gulp-cli @@v\d.\d.\d@@ | gulp @@v\d.\d.\d@@\n/;
+
+    var opts = { cwd: cwd };
+    exec(gulp('--version'), opts, cb);
+
+    function cb(err, stdout, stderr) {
+      expect(err).toBeNull();
+      expect(stderr).toEqual('');
+      expect(stdout).toMatch(expected);
+      done(err);
+    }
+  });
+
+  it('Should change info.cwdChanged with .gulp.*', function(done) {
+    var cwd = path.join(baseDir, 'info/cwdChanged');
+    var gulpfile = tildify(path.join(cwd, 'gulpfile.js'));
+    var expected = 'CHANGE CWD TO  **' + tildify(cwd) + '**\n' +
+      'Using gulpfile ' + gulpfile + '\n' +
+      'Starting \'default\'...\n' +
+      'Finished \'default\' after ?\n';
+
+    var opts = { cwd: baseDir };
+    exec(gulp('--cwd ' + cwd), opts, cb);
+
+    function cb(err, stdout, stderr) {
+      expect(err).toBeNull();
+      expect(stderr).toEqual('');
+      expect(eraseLapse(eraseTime(stdout))).toEqual(expected);
+      done(err);
+    }
+  });
+
+  it('Should change info.usingGulpfile with .gulp.*', function(done) {
+    var cwd = path.join(baseDir, 'info/usingGulpfile');
+    var gulpfile = tildify(path.join(cwd, 'gulpfile.js'));
+    var expected = 'USING GULPFILE **' + gulpfile + '**\n' +
+      'Starting \'default\'...\n' +
+      'Finished \'default\' after ?\n';
+
+    var opts = { cwd: cwd };
+    exec(gulp(), opts, cb);
+
+    function cb(err, stdout, stderr) {
+      expect(err).toBeNull();
+      expect(stderr).toEqual('');
+      expect(eraseLapse(eraseTime(stdout))).toEqual(expected);
+      done(err);
+    }
+  });
+
+  it('Should change info.taskStart with .gulp.*', function(done) {
+    var cwd = path.join(baseDir, 'info/taskStart');
+    var gulpfile = tildify(path.join(cwd, 'gulpfile.js'));
+    var expected = 'Using gulpfile ' + gulpfile + '\n' +
+      'START **default**\n' +
+      'Finished \'default\' after ?\n';
+
+    var opts = { cwd: cwd };
+    exec(gulp(), opts, cb);
+
+    function cb(err, stdout, stderr) {
+      expect(err).toBeNull();
+      expect(stderr).toEqual('');
+      expect(eraseLapse(eraseTime(stdout))).toEqual(expected);
+      done(err);
+    }
+  });
+
+  it('Should change info.taskStop with .gulp.*', function(done) {
+    var cwd = path.join(baseDir, 'info/taskStop');
+    var gulpfile = tildify(path.join(cwd, 'gulpfile.js'));
+    var expected = 'Using gulpfile ' + gulpfile + '\n' +
+      'Starting \'default\'...\n' +
+      'STOP **default**\n';
+
+    var opts = { cwd: cwd };
+    exec(gulp(), opts, cb);
+
+    function cb(err, stdout, stderr) {
+      expect(err).toBeNull();
+      expect(stderr).toEqual('');
+      expect(eraseTime(stdout)).toEqual(expected);
+      done(err);
+    }
+  });
+
+  it('Should change warn.preloadFailure with .gulp.*', function(done) {
+    var cwd = path.join(baseDir, 'warn/preloadFailure');
+    var gulpfile = tildify(path.join(cwd, 'gulpfile.js'));
+    var expected = 'Preloading external module: null-module\n' +
+      'FAILED TO PRELOAD **null-module**\n' +
+      'Using gulpfile ' + gulpfile + '\n' +
+      'Starting \'default\'...\n' +
+      'Finished \'default\' after ?\n';
+
+    var opts = { cwd: cwd };
+    exec(gulp('--preload null-module'), opts, cb);
+
+    function cb(err, stdout, stderr) {
+      expect(err).toBeNull();
+      expect(stderr).toEqual('');
+      expect(eraseLapse(eraseTime(stdout))).toEqual(expected);
+      done(err);
+    }
+  });
+
+  it('Should change warn.loaderFailure with .gulp.*', function(done) {
+    var cwd = path.join(baseDir, 'warn/loaderFailure');
+    var expected = 'FAIL TO LOAD **coffeescript/register**\n';
+
+    var opts = { cwd: cwd };
+    exec(gulp('-f gulpfile.coffee'), opts, cb);
+
+    function cb(err, stdout, stderr) {
+      expect(err).not.toBeNull();
+      expect(stderr).not.toEqual('');
+      expect(eraseTime(stdout)).toEqual(expected);
+      done();
+    }
+  });
+
+  it('Should change warn.taskNotComplete with .gulp.*', function(done) {
+    var cwd = path.join(baseDir, 'warn/taskNotComplete');
+    var gulpfile = tildify(path.join(cwd, 'gulpfile.js'));
+    var expected = 'Using gulpfile ' + gulpfile + '\n' +
+      'Starting \'default\'...\n' +
+      'TASK **default** DID NOT COMPLETE\n';
+
+    var opts = { cwd: cwd };
+    exec(gulp(), opts, cb);
+
+    function cb(err, stdout, stderr) {
+      expect(err).not.toBeNull();
+      expect(stderr).toEqual('');
+      expect(eraseTime(stdout)).toEqual(expected);
+      done();
+    }
+  });
+
+  it('Should change error.gulpNotFound with .gulp.*', function(done) {
+    var dir = path.join(baseDir, 'error/gulpNotFound');
+    var cwd = os.tmpdir();
+    fs.copyFileSync(path.join(dir, '.gulp.js'), path.join(cwd, '.gulp.js'));
+
+    var opts = { cwd: cwd };
+    exec(gulp(), opts, cb);
+
+    if (os.platform() === 'darwin') {
+      cwd = path.join('/private', cwd);
+    }
+    var expected = 'GULP NOT FOUND IN **' + cwd + '**\n';
+
+    function cb(err, stdout, stderr) {
+      try {
+        expect(err).not.toBeNull();
+        expect(stdout).toEqual('');
+        expect(stderr).toEqual(expected);
+        done();
+      } finally {
+        fs.unlinkSync(path.join(cwd, '.gulp.js'));
+      }
+    }
+  });
+
+  it('Should change error.nodeModulesNotFound with .gulp.*', function(done) {
+    var dir = path.join(baseDir, 'error/nodeModulesNotFound');
+    var cwd = os.tmpdir();
+    fs.copyFileSync(path.join(dir, '.gulp.js'), path.join(cwd, '.gulp.js'));
+    fs.copyFileSync(path.join(dir, 'package.json'), path.join(cwd, 'package.json'));
+    var opts = { cwd: cwd };
+    exec(gulp(), opts, cb);
+
+    if (os.platform() === 'darwin') {
+      cwd = path.join('/private', cwd);
+    }
+    var expected = 'LOCAL MODULE NOT FOUND **' + cwd + '**\n';
+
+    function cb(err, stdout, stderr) {
+      try {
+        expect(err).not.toBeNull();
+        expect(stdout).toEqual('');
+        expect(stderr).toEqual(expected);
+        done();
+      } finally {
+        fs.unlinkSync(path.join(cwd, '.gulp.js'));
+        fs.unlinkSync(path.join(cwd, 'package.json'));
+      }
+    }
+  });
+
+  it('Should change error.gulpfileNotFound with .gulp.*', function(done) {
+    var cwd = path.join(baseDir, 'error/gulpfileNotFound');
+    var expected = 'NO GULPFILE\n';
+
+    var opts = { cwd: cwd };
+    exec(gulp(), opts, cb);
+
+    function cb(err, stdout, stderr) {
+      expect(err).not.toBeNull();
+      expect(stdout).toEqual('');
+      expect(eraseTime(stderr)).toEqual(expected);
+      done();
+    }
+  });
+
+  it('Should change error.badGulpVersion with .gulp.*', function(done) {
+    var cwd = path.join(baseDir, 'error/badGulpVersion');
+    var expected = 'BAD GULP VERSION **1.2.3**\n';
+
+    var opts = { cwd: cwd };
+    exec(gulp(), opts, cb);
+
+    function cb(err, stdout, stderr) {
+      expect(err).not.toBeNull();
+      expect(stdout).toEqual('');
+      expect(eraseTime(stderr)).toEqual(expected);
+      done();
+    }
+  });
+
+  it('Should change error.taskError with .gulp.*', function(done) {
+    var cwd = path.join(baseDir, 'error/taskError');
+    var gulpfile = tildify(path.join(cwd, 'gulpfile.js'));
+    var expectedStdout = 'Using gulpfile ' + gulpfile + '\n' +
+      'Starting \'default\'...\n';
+    var expectedStderr = 'TASK ERROR: **default**\n';
+
+    var opts = { cwd: cwd };
+    exec(gulp(), opts, cb);
+
+    function cb(err, stdout, stderr) {
+      expect(err).not.toBeNull();
+      expect(eraseTime(stderr)).toEqual(expectedStderr);
+      expect(eraseTime(stdout)).toEqual(expectedStdout);
+      done();
+    }
+  });
+
+  it('Should change error.taskNotFound with .gulp.*', function(done) {
+    var cwd = path.join(baseDir, 'error/taskNotFound');
+    var gulpfile = tildify(path.join(cwd, 'gulpfile.js'));
+    var expectedStdout = 'Using gulpfile ' + gulpfile + '\n';
+    var expectedStderr = 'TASK IS NOT FOUND: **defaults** SIMILAR ##default##';
+
+    var opts = { cwd: cwd };
+    exec(gulp('defaults'), opts, cb);
+
+    function cb(err, stdout, stderr) {
+      expect(err).not.toBeNull();
+      expect(eraseTime(stderr)).toMatch(expectedStderr);
+      expect(eraseTime(stdout)).toEqual(expectedStdout);
+      done();
+    }
+  });
+
+  it('Should change error.failToRun with .gulp.*', function(done) {
+    var cwd = path.join(baseDir, 'error/failToRun');
+    var expected = 'FAIL TO RUN\n';
+
+    var opts = { cwd: cwd };
+    exec(gulp(), opts, cb);
+
+    function cb(err, stdout, stderr) {
+      expect(err).not.toBeNull();
+      expect(stderr).toEqual(expected);
+      expect(stdout).toEqual('');
+      done();
+    }
+  });
+
+  it('Should change error.noCompletionType with .gulp.*', function(done) {
+    var cwd = path.join(baseDir, 'error/noCompletionType');
+    var expected = 'NO COMPLETION TYPE';
+
+    var opts = { cwd: cwd };
+    exec(gulp('--completion'), opts, cb);
+
+    function cb(err, stdout, stderr) {
+      expect(err).not.toBeNull();
+      expect(stderr).toMatch(expected);
+      expect(stdout).toEqual('');
+      done();
+    }
+  });
+
+  it('Should change error.unknownCompletionType with .gulp.*', function(done) {
+    var cwd = path.join(baseDir, 'error/unknownCompletionType');
+    var expected = 'GULP COMPLETION TYPE **xxx** IS NOT FOUND\n';
+
+    var opts = { cwd: cwd };
+    exec(gulp('--completion=xxx'), opts, cb);
+
+    function cb(err, stdout, stderr) {
+      expect(err).not.toBeNull();
+      expect(stderr).toEqual('');
+      expect(stdout).toEqual(expected);
+      done();
+    }
+  });
+});
diff --git a/test/execution-errors.js b/test/execution-errors.js
index 769832a9..7b2fd1ec 100644
--- a/test/execution-errors.js
+++ b/test/execution-errors.js
@@ -4,6 +4,7 @@ var expect = require('expect');
 var exec = require('child_process').exec;
 var path = require('path');
 var os = require('os');
+var fs = require('fs');
 
 var tildify = require('../lib/shared/tildify');
 
@@ -29,6 +30,21 @@ describe('execution error', function() {
     }
   });
 
+  it('should output an error if a task is not defined but a similar task is found', function(done) {
+    var opts = { cwd: path.join(__dirname, './fixtures/gulpfiles') };
+    exec(gulp('test0'), opts, cb);
+
+    function cb(err, stdout, stderr) {
+      expect(err).not.toBeNull();
+      expect(err.code).toEqual(1);
+      expect(eraseTime(stdout)).toMatch('Using gulpfile ');
+      expect(eraseTime(stderr)).toEqual(
+        'Task never defined: test0 - did you mean? test1, test2, test3, test4, test5, test6, test7, test8\n' +
+        'To list available tasks, try running: gulp --tasks\n');
+      done();
+    }
+  });
+
   it('should output an error if gulp version is unsupported', function(done) {
     var opts = { cwd: path.join(__dirname, './fixtures/errors/bad-gulp-version') };
     exec(gulp(), opts, cb);
@@ -42,7 +58,7 @@ describe('execution error', function() {
     }
   });
 
-  it('should output an error if gulp is not found', function(done) {
+  it('should output an error if gulp is not found (npm)', function(done) {
     var opts = { cwd: os.tmpdir() };
     exec(gulp(), opts, cb);
 
@@ -55,6 +71,79 @@ describe('execution error', function() {
     }
   });
 
+  it('should output an error if gulp is not found (yarn)', function(done) {
+    var cwd = os.tmpdir();
+    var yarnOrig= path.join(__dirname, 'fixtures/errors/yarn/yarn.lock');
+    var yarnLock = path.join(cwd, 'yarn.lock');
+
+    fs.copyFileSync(yarnOrig, yarnLock);
+
+    var opts = { cwd: cwd };
+    exec(gulp(), opts, cb);
+
+    function cb(err, stdout, stderr) {
+      try {
+        expect(err).not.toBeNull();
+        expect(err.code).toEqual(1);
+        expect(sliceLines(stderr, 0, 1)).toMatch('Local gulp not found in ');
+        expect(sliceLines(stderr, 1, 2)).toEqual('Try running: yarn add gulp');
+        done();
+      } finally {
+        fs.unlinkSync(yarnLock);
+      }
+    }
+  });
+
+  it('should output an error if local modules are not found (npm)', function(done) {
+    var cwd = os.tmpdir();
+    var pkgOrig = path.join(__dirname, 'fixtures/errors/package.json');
+    var pkgJson = path.join(cwd, 'package.json');
+
+    fs.copyFileSync(pkgOrig, pkgJson);
+
+    var opts = { cwd: cwd };
+    exec(gulp(), opts, cb);
+
+    function cb(err, stdout, stderr) {
+      try {
+        expect(err).not.toBeNull();
+        expect(err.code).toEqual(1);
+        expect(sliceLines(stderr, 0, 1)).toMatch('Local modules not found in ');
+        expect(sliceLines(stderr, 1, 2)).toEqual('Try running: npm install');
+        done();
+      } finally {
+        fs.unlinkSync(pkgJson);
+      }
+    }
+  });
+
+  it('should output an error if local modules are not found (yarn)', function(done) {
+    var cwd = os.tmpdir();
+    var pkgOrig = path.join(__dirname, 'fixtures/errors/package.json');
+    var pkgJson = path.join(cwd, 'package.json');
+    var yarnOrig= path.join(__dirname, 'fixtures/errors/yarn/yarn.lock');
+    var yarnLock = path.join(cwd, 'yarn.lock');
+
+    fs.copyFileSync(pkgOrig, pkgJson);
+    fs.copyFileSync(yarnOrig, yarnLock);
+
+    var opts = { cwd: cwd };
+    exec(gulp(), opts, cb);
+
+    function cb(err, stdout, stderr) {
+      try {
+        expect(err).not.toBeNull();
+        expect(err.code).toEqual(1);
+        expect(sliceLines(stderr, 0, 1)).toMatch('Local modules not found in ');
+        expect(sliceLines(stderr, 1, 2)).toEqual('Try running: yarn install');
+        done();
+      } finally {
+        fs.unlinkSync(pkgJson);
+        fs.unlinkSync(yarnLock);
+      }
+    }
+  });
+
   it('should log a same error once', function(done) {
     var dir = path.join(__dirname, 'fixtures/gulpfiles');
     var gulpfileName = 'gulpfile-dedup-errorlog.js';
diff --git a/test/expected/config/theming/help/flags/help.txt b/test/expected/config/theming/help/flags/help.txt
new file mode 100644
index 00000000..3fae82da
--- /dev/null
+++ b/test/expected/config/theming/help/flags/help.txt
@@ -0,0 +1,21 @@
+
+Usage: gulp [options] tasks
+
+Options:
+  -h, --help                  **HELP**                                 [boolean]
+  -v, --version               **VERSION**                              [boolean]
+      --preload               **PRELOAD**                               [string]
+  -f, --gulpfile              **GULPFILE**                              [string]
+      --cwd                   **CWD**                                   [string]
+  -T, --tasks                 **TASKS**                                [boolean]
+      --tasks-simple          **TASKS SIMPLE**                         [boolean]
+      --tasks-json            **TASKS JSON**
+      --tasks-depth, --depth  **TASKS DEPTH**                           [number]
+      --compact-tasks         **COMPACT TASKS**                        [boolean]
+      --sort-tasks            **SORT_TASKS**                           [boolean]
+      --color                 **COLOR**                                [boolean]
+      --no-color              **NO COLOR**                             [boolean]
+  -S, --silent                **SILENT**                               [boolean]
+      --continue              **CONTINUE**                             [boolean]
+      --series                **SERIES**                               [boolean]
+  -L, --log-level             **LOG LEVEL**                              [count]
diff --git a/test/expected/config/theming/help/usage/help.txt b/test/expected/config/theming/help/usage/help.txt
new file mode 100644
index 00000000..b03f78bd
--- /dev/null
+++ b/test/expected/config/theming/help/usage/help.txt
@@ -0,0 +1,39 @@
+GULP USAGE
+
+Options:
+  -h, --help                  Show this help.                          [boolean]
+  -v, --version               Print the global and local gulp versions.[boolean]
+      --preload               Will preload a module before running the gulpfile.
+                              This is useful for transpilers but also has other
+                              applications.                             [string]
+  -f, --gulpfile              Manually set path of gulpfile. Useful if you have
+                              multiple gulpfiles. This will set the CWD to the
+                              gulpfile directory as well.               [string]
+      --cwd                   Manually set the CWD. The search for the gulpfile,
+                              as well as the relativity of all requires will be
+                              from here.                                [string]
+  -T, --tasks                 Print the task dependency tree for the loaded
+                              gulpfile.                                [boolean]
+      --tasks-simple          Print a plaintext list of tasks for the loaded
+                              gulpfile.                                [boolean]
+      --tasks-json            Print the task dependency tree, in JSON format,
+                              for the loaded gulpfile.
+      --tasks-depth, --depth  Specify the depth of the task dependency tree.
+                                                                        [number]
+      --compact-tasks         Reduce the output of task dependency tree by
+                              printing only top tasks and their child tasks.
+                                                                       [boolean]
+      --sort-tasks            Will sort top tasks of task dependency tree.
+                                                                       [boolean]
+      --color                 Will force gulp and gulp plugins to display
+                              colors, even when no color support is detected.
+                                                                       [boolean]
+      --no-color              Will force gulp and gulp plugins to not display
+                              colors, even when color support is detected.
+                                                                       [boolean]
+  -S, --silent                Suppress all gulp logging.               [boolean]
+      --continue              Continue execution of tasks upon failure.[boolean]
+      --series                Run tasks given on the CLI in series (the default
+                              is parallel).                            [boolean]
+  -L, --log-level             Set the loglevel. -L for least verbose and -LLLL
+                              for most verbose. -LLL is default.         [count]
diff --git a/test/fixtures/config/theming/error/badGulpVersion/.gulp.js b/test/fixtures/config/theming/error/badGulpVersion/.gulp.js
new file mode 100644
index 00000000..d923bd09
--- /dev/null
+++ b/test/fixtures/config/theming/error/badGulpVersion/.gulp.js
@@ -0,0 +1,10 @@
+module.exports = {
+  msgs: {
+    error: {
+      badGulpVersion: '{TIMESTAMP}BAD GULP VERSION {GulpVer:{1}}',
+    },
+  },
+  theme: {
+    GulpVer: '**{1}**',
+  },
+};
diff --git a/test/fixtures/config/theming/error/badGulpVersion/gulpfile.js b/test/fixtures/config/theming/error/badGulpVersion/gulpfile.js
new file mode 100644
index 00000000..db73dd16
--- /dev/null
+++ b/test/fixtures/config/theming/error/badGulpVersion/gulpfile.js
@@ -0,0 +1,3 @@
+exports.default = function(done) {
+  done();
+}
diff --git a/test/fixtures/config/theming/error/badGulpVersion/node_modules/gulp/index.js b/test/fixtures/config/theming/error/badGulpVersion/node_modules/gulp/index.js
new file mode 100644
index 00000000..e69de29b
diff --git a/test/fixtures/config/theming/error/badGulpVersion/node_modules/gulp/package.json b/test/fixtures/config/theming/error/badGulpVersion/node_modules/gulp/package.json
new file mode 100644
index 00000000..dbe8ece4
--- /dev/null
+++ b/test/fixtures/config/theming/error/badGulpVersion/node_modules/gulp/package.json
@@ -0,0 +1,15 @@
+{
+  "name": "gulp",
+  "description": "Test Package for Testing!",
+  "version": "1.2.3",
+  "tags": [
+  ],
+  "files": [
+  ],
+  "licenses": [
+    {
+      "type": "MIT",
+      "url": "https://raw.githubusercontent.com/gulpjs/gulp/master/LICENSE"
+    }
+  ]
+}
diff --git a/test/fixtures/config/theming/error/failToRun/.gulp.js b/test/fixtures/config/theming/error/failToRun/.gulp.js
new file mode 100644
index 00000000..c93d52de
--- /dev/null
+++ b/test/fixtures/config/theming/error/failToRun/.gulp.js
@@ -0,0 +1,8 @@
+module.exports = {
+  msgs: {
+    info: null,  // To cause failToRun error forcefully
+    error: {
+      failToRun: 'FAIL TO RUN',
+    },
+  },
+};
diff --git a/test/fixtures/config/theming/error/failToRun/gulpfile.js b/test/fixtures/config/theming/error/failToRun/gulpfile.js
new file mode 100644
index 00000000..db73dd16
--- /dev/null
+++ b/test/fixtures/config/theming/error/failToRun/gulpfile.js
@@ -0,0 +1,3 @@
+exports.default = function(done) {
+  done();
+}
diff --git a/test/fixtures/config/theming/error/gulpNotFound/.gulp.js b/test/fixtures/config/theming/error/gulpNotFound/.gulp.js
new file mode 100644
index 00000000..3d8bb0b4
--- /dev/null
+++ b/test/fixtures/config/theming/error/gulpNotFound/.gulp.js
@@ -0,0 +1,10 @@
+module.exports = {
+  msgs: {
+    error: {
+      gulpNotFound: 'GULP NOT FOUND IN {CwdPath: {1}}',
+    },
+  },
+  theme: {
+    CwdPath: '**{1}**',
+  },
+};
diff --git a/test/fixtures/config/theming/error/gulpfileNotFound/.gulp.js b/test/fixtures/config/theming/error/gulpfileNotFound/.gulp.js
new file mode 100644
index 00000000..a96938cb
--- /dev/null
+++ b/test/fixtures/config/theming/error/gulpfileNotFound/.gulp.js
@@ -0,0 +1,7 @@
+module.exports = {
+  msgs: {
+    error: {
+      gulpfileNotFound: '{TIMESTAMP}NO GULPFILE',
+    },
+  },
+};
diff --git a/test/fixtures/config/theming/error/noCompletionType/.gulp.js b/test/fixtures/config/theming/error/noCompletionType/.gulp.js
new file mode 100644
index 00000000..6817dbf5
--- /dev/null
+++ b/test/fixtures/config/theming/error/noCompletionType/.gulp.js
@@ -0,0 +1,7 @@
+module.exports = {
+  msgs: {
+    error: {
+      noCompletionType: 'NO COMPLETION TYPE',
+    },
+  },
+};
diff --git a/test/fixtures/config/theming/error/noCompletionType/gulpfile.js b/test/fixtures/config/theming/error/noCompletionType/gulpfile.js
new file mode 100644
index 00000000..db73dd16
--- /dev/null
+++ b/test/fixtures/config/theming/error/noCompletionType/gulpfile.js
@@ -0,0 +1,3 @@
+exports.default = function(done) {
+  done();
+}
diff --git a/test/fixtures/config/theming/error/nodeModulesNotFound/.gulp.js b/test/fixtures/config/theming/error/nodeModulesNotFound/.gulp.js
new file mode 100644
index 00000000..2576d4cc
--- /dev/null
+++ b/test/fixtures/config/theming/error/nodeModulesNotFound/.gulp.js
@@ -0,0 +1,12 @@
+var os = require('os');
+
+module.exports = {
+  msgs: {
+    error: {
+      nodeModulesNotFound: 'LOCAL MODULE NOT FOUND {Path: {1}}',
+    },
+  },
+  theme: {
+    Path: '**{1}**',
+  },
+};
diff --git a/test/fixtures/config/theming/error/nodeModulesNotFound/package.json b/test/fixtures/config/theming/error/nodeModulesNotFound/package.json
new file mode 100644
index 00000000..109ec6a8
--- /dev/null
+++ b/test/fixtures/config/theming/error/nodeModulesNotFound/package.json
@@ -0,0 +1,12 @@
+{
+  "name": "nodeModulesNotFound",
+  "version": "1.0.0",
+  "description": "",
+  "main": ".gulp.js",
+  "scripts": {
+    "test": "echo \"Error: no test specified\" && exit 1"
+  },
+  "keywords": [],
+  "author": "",
+  "license": "ISC"
+}
diff --git a/test/fixtures/config/theming/error/taskError/.gulp.js b/test/fixtures/config/theming/error/taskError/.gulp.js
new file mode 100644
index 00000000..534a1456
--- /dev/null
+++ b/test/fixtures/config/theming/error/taskError/.gulp.js
@@ -0,0 +1,10 @@
+module.exports = {
+  msgs: {
+    error: {
+      taskError: '{TIMESTAMP}TASK ERROR: {TaskName:{1}}',
+    },
+  },
+  theme: {
+    TaskName: '**{1}**',
+  },
+};
diff --git a/test/fixtures/config/theming/error/taskError/gulpfile.js b/test/fixtures/config/theming/error/taskError/gulpfile.js
new file mode 100644
index 00000000..eeb90fd6
--- /dev/null
+++ b/test/fixtures/config/theming/error/taskError/gulpfile.js
@@ -0,0 +1,3 @@
+exports.default = function(done) {
+  throw new Error('FAIL!');
+}
diff --git a/test/fixtures/config/theming/error/taskNotFound/.gulp.js b/test/fixtures/config/theming/error/taskNotFound/.gulp.js
new file mode 100644
index 00000000..12545808
--- /dev/null
+++ b/test/fixtures/config/theming/error/taskNotFound/.gulp.js
@@ -0,0 +1,11 @@
+module.exports = {
+  msgs: {
+    error: {
+      taskNotFound: '{TIMESTAMP}TASK IS NOT FOUND: {TaskName:{1}}{IF:{2}? SIMILAR {SimilarTasks:{3}}}',
+    },
+  },
+  theme: {
+    TaskName: '**{1}**',
+    SimilarTasks: '##{1}##',
+  },
+};
diff --git a/test/fixtures/config/theming/error/taskNotFound/gulpfile.js b/test/fixtures/config/theming/error/taskNotFound/gulpfile.js
new file mode 100644
index 00000000..db73dd16
--- /dev/null
+++ b/test/fixtures/config/theming/error/taskNotFound/gulpfile.js
@@ -0,0 +1,3 @@
+exports.default = function(done) {
+  done();
+}
diff --git a/test/fixtures/config/theming/error/unknownCompletionType/.gulp.js b/test/fixtures/config/theming/error/unknownCompletionType/.gulp.js
new file mode 100644
index 00000000..0676f0a8
--- /dev/null
+++ b/test/fixtures/config/theming/error/unknownCompletionType/.gulp.js
@@ -0,0 +1,10 @@
+module.exports = {
+  msgs: {
+    error: {
+      unknownCompletionType: 'GULP COMPLETION TYPE {Type: {1}} IS NOT FOUND',
+    },
+  },
+  theme: {
+    Type: '**{1}**',
+  },
+};
diff --git a/test/fixtures/config/theming/error/unknownCompletionType/gulpfile.js b/test/fixtures/config/theming/error/unknownCompletionType/gulpfile.js
new file mode 100644
index 00000000..db73dd16
--- /dev/null
+++ b/test/fixtures/config/theming/error/unknownCompletionType/gulpfile.js
@@ -0,0 +1,3 @@
+exports.default = function(done) {
+  done();
+}
diff --git a/test/fixtures/config/theming/help/flags/.gulp.js b/test/fixtures/config/theming/help/flags/.gulp.js
new file mode 100644
index 00000000..1a008528
--- /dev/null
+++ b/test/fixtures/config/theming/help/flags/.gulp.js
@@ -0,0 +1,28 @@
+module.exports = {
+  msgs: {
+    help: {
+      flags: {
+        help: '{help_desc: HELP}',
+        version: '{help_desc: VERSION}',
+        preload: '{help_desc: PRELOAD}',
+        gulpfile: '{help_desc: GULPFILE}',
+        cwd: '{help_desc: CWD}',
+        tasks: '{help_desc: TASKS}',
+        'tasks-simple': '{help_desc: TASKS SIMPLE}',
+        'tasks-json': '{help_desc: TASKS JSON}',
+        'tasks-depth': '{help_desc: TASKS DEPTH}',
+        'compact-tasks': '{help_desc: COMPACT TASKS}',
+        'sort-tasks': '{help_desc: SORT_TASKS}',
+        color: '{help_desc: COLOR}',
+        'no-color': '{help_desc: NO COLOR}',
+        silent: '{help_desc: SILENT}',
+        continue: '{help_desc: CONTINUE}',
+        series: '{help_desc: SERIES}',
+        'log-level': '{help_desc: LOG LEVEL}',
+      },
+    },
+  },
+  theme: {
+    help_desc: '**{1}**',
+  },
+};
diff --git a/test/fixtures/config/theming/help/usage/.gulp.js b/test/fixtures/config/theming/help/usage/.gulp.js
new file mode 100644
index 00000000..f96d44df
--- /dev/null
+++ b/test/fixtures/config/theming/help/usage/.gulp.js
@@ -0,0 +1,7 @@
+module.exports = {
+  msgs: {
+    help: {
+      usage: 'GULP USAGE',
+    },
+  },
+};
diff --git a/test/fixtures/config/theming/info/cwdChanged/.gulp.js b/test/fixtures/config/theming/info/cwdChanged/.gulp.js
new file mode 100644
index 00000000..3c3c9380
--- /dev/null
+++ b/test/fixtures/config/theming/info/cwdChanged/.gulp.js
@@ -0,0 +1,10 @@
+module.exports = {
+  msgs: {
+    info: {
+      cwdChanged: '{TIMESTAMP}CHANGE CWD TO  {CwdPath: {1}}',
+    },
+  },
+  theme: {
+    CwdPath: '**{1}**',
+  },
+};
diff --git a/test/fixtures/config/theming/info/cwdChanged/gulpfile.js b/test/fixtures/config/theming/info/cwdChanged/gulpfile.js
new file mode 100644
index 00000000..db73dd16
--- /dev/null
+++ b/test/fixtures/config/theming/info/cwdChanged/gulpfile.js
@@ -0,0 +1,3 @@
+exports.default = function(done) {
+  done();
+}
diff --git a/test/fixtures/config/theming/info/loaderSuccess/.gulp.js b/test/fixtures/config/theming/info/loaderSuccess/.gulp.js
new file mode 100644
index 00000000..ec7df4a5
--- /dev/null
+++ b/test/fixtures/config/theming/info/loaderSuccess/.gulp.js
@@ -0,0 +1,10 @@
+module.exports = {
+  msgs: {
+    info: {
+      loaderSuccess: 'LOADED {ModuleName: {1}}',
+    },
+  },
+  theme: {
+    ModuleName: '**{1}**',
+  },
+};
diff --git a/test/fixtures/config/theming/info/loaderSuccess/gulpfile.babel.js b/test/fixtures/config/theming/info/loaderSuccess/gulpfile.babel.js
new file mode 100644
index 00000000..db73dd16
--- /dev/null
+++ b/test/fixtures/config/theming/info/loaderSuccess/gulpfile.babel.js
@@ -0,0 +1,3 @@
+exports.default = function(done) {
+  done();
+}
diff --git a/test/fixtures/config/theming/info/preloadBefore/.gulp.js b/test/fixtures/config/theming/info/preloadBefore/.gulp.js
new file mode 100644
index 00000000..a6744dda
--- /dev/null
+++ b/test/fixtures/config/theming/info/preloadBefore/.gulp.js
@@ -0,0 +1,10 @@
+module.exports = {
+  msgs: {
+    info: {
+      preloadBefore: 'PRELOADING {ModuleName: {1}}',
+    },
+  },
+  theme: {
+    ModuleName: '**{1}**',
+  },
+};
diff --git a/test/fixtures/config/theming/info/preloadBefore/gulpfile.js b/test/fixtures/config/theming/info/preloadBefore/gulpfile.js
new file mode 100644
index 00000000..db73dd16
--- /dev/null
+++ b/test/fixtures/config/theming/info/preloadBefore/gulpfile.js
@@ -0,0 +1,3 @@
+exports.default = function(done) {
+  done();
+}
diff --git a/test/fixtures/config/theming/info/preloadBefore/preload.js b/test/fixtures/config/theming/info/preloadBefore/preload.js
new file mode 100644
index 00000000..3b5d0c74
--- /dev/null
+++ b/test/fixtures/config/theming/info/preloadBefore/preload.js
@@ -0,0 +1 @@
+global.preload = 'hello preload!';
diff --git a/test/fixtures/config/theming/info/preloadSuccess/.gulp.js b/test/fixtures/config/theming/info/preloadSuccess/.gulp.js
new file mode 100644
index 00000000..bd6497e2
--- /dev/null
+++ b/test/fixtures/config/theming/info/preloadSuccess/.gulp.js
@@ -0,0 +1,10 @@
+module.exports = {
+  msgs: {
+    info: {
+      preloadSuccess: 'PRELOADDED {ModuleName: {1}}',
+    },
+  },
+  theme: {
+    ModuleName: '**{1}**',
+  },
+};
diff --git a/test/fixtures/config/theming/info/preloadSuccess/gulpfile.js b/test/fixtures/config/theming/info/preloadSuccess/gulpfile.js
new file mode 100644
index 00000000..db73dd16
--- /dev/null
+++ b/test/fixtures/config/theming/info/preloadSuccess/gulpfile.js
@@ -0,0 +1,3 @@
+exports.default = function(done) {
+  done();
+}
diff --git a/test/fixtures/config/theming/info/preloadSuccess/preload.js b/test/fixtures/config/theming/info/preloadSuccess/preload.js
new file mode 100644
index 00000000..3b5d0c74
--- /dev/null
+++ b/test/fixtures/config/theming/info/preloadSuccess/preload.js
@@ -0,0 +1 @@
+global.preload = 'hello preload!';
diff --git a/test/fixtures/config/theming/info/respawn/.gulp.js b/test/fixtures/config/theming/info/respawn/.gulp.js
new file mode 100644
index 00000000..8f6de9e3
--- /dev/null
+++ b/test/fixtures/config/theming/info/respawn/.gulp.js
@@ -0,0 +1,10 @@
+module.exports = {
+  msgs: {
+    info: {
+      respawn: 'RESPAWN BY {NodeFlag: {1}}',
+    },
+  },
+  theme: {
+    NodeFlag: '**{1}**',
+  },
+};
diff --git a/test/fixtures/config/theming/info/respawn/gulpfile.js b/test/fixtures/config/theming/info/respawn/gulpfile.js
new file mode 100644
index 00000000..db73dd16
--- /dev/null
+++ b/test/fixtures/config/theming/info/respawn/gulpfile.js
@@ -0,0 +1,3 @@
+exports.default = function(done) {
+  done();
+}
diff --git a/test/fixtures/config/theming/info/taskStart/.gulp.js b/test/fixtures/config/theming/info/taskStart/.gulp.js
new file mode 100644
index 00000000..c1cef5d1
--- /dev/null
+++ b/test/fixtures/config/theming/info/taskStart/.gulp.js
@@ -0,0 +1,10 @@
+module.exports = {
+  msgs: {
+    info: {
+      taskStart: '{TIMESTAMP}START {Task: {1}}',
+    },
+  },
+  theme: {
+    Task: '**{1}**',
+  },
+};
diff --git a/test/fixtures/config/theming/info/taskStart/gulpfile.js b/test/fixtures/config/theming/info/taskStart/gulpfile.js
new file mode 100644
index 00000000..db73dd16
--- /dev/null
+++ b/test/fixtures/config/theming/info/taskStart/gulpfile.js
@@ -0,0 +1,3 @@
+exports.default = function(done) {
+  done();
+}
diff --git a/test/fixtures/config/theming/info/taskStop/.gulp.js b/test/fixtures/config/theming/info/taskStop/.gulp.js
new file mode 100644
index 00000000..7c62298c
--- /dev/null
+++ b/test/fixtures/config/theming/info/taskStop/.gulp.js
@@ -0,0 +1,10 @@
+module.exports = {
+  msgs: {
+    info: {
+      taskStop: '{TIMESTAMP}STOP {Task: {1}}',
+    },
+  },
+  theme: {
+    Task: '**{1}**',
+  },
+};
diff --git a/test/fixtures/config/theming/info/taskStop/gulpfile.js b/test/fixtures/config/theming/info/taskStop/gulpfile.js
new file mode 100644
index 00000000..db73dd16
--- /dev/null
+++ b/test/fixtures/config/theming/info/taskStop/gulpfile.js
@@ -0,0 +1,3 @@
+exports.default = function(done) {
+  done();
+}
diff --git a/test/fixtures/config/theming/info/usingGulpfile/.gulp.js b/test/fixtures/config/theming/info/usingGulpfile/.gulp.js
new file mode 100644
index 00000000..cea0669a
--- /dev/null
+++ b/test/fixtures/config/theming/info/usingGulpfile/.gulp.js
@@ -0,0 +1,10 @@
+module.exports = {
+  msgs: {
+    info: {
+      usingGulpfile: '{TIMESTAMP}USING GULPFILE {File:{1}}',
+    },
+  },
+  theme: {
+    File: '**{1}**',
+  },
+};
diff --git a/test/fixtures/config/theming/info/usingGulpfile/gulpfile.js b/test/fixtures/config/theming/info/usingGulpfile/gulpfile.js
new file mode 100644
index 00000000..db73dd16
--- /dev/null
+++ b/test/fixtures/config/theming/info/usingGulpfile/gulpfile.js
@@ -0,0 +1,3 @@
+exports.default = function(done) {
+  done();
+}
diff --git a/test/fixtures/config/theming/info/version/.gulp.js b/test/fixtures/config/theming/info/version/.gulp.js
new file mode 100644
index 00000000..4183557c
--- /dev/null
+++ b/test/fixtures/config/theming/info/version/.gulp.js
@@ -0,0 +1,10 @@
+module.exports = {
+  msgs: {
+    info: {
+      version: 'gulp-cli {VERSION: v{1}} | gulp {VERSION: v{2}}',
+    },
+  },
+  theme: {
+    VERSION: '@@{1}@@',
+  },
+};
diff --git a/test/fixtures/config/theming/tasks/childTask/.gulp.js b/test/fixtures/config/theming/tasks/childTask/.gulp.js
new file mode 100644
index 00000000..545b70f9
--- /dev/null
+++ b/test/fixtures/config/theming/tasks/childTask/.gulp.js
@@ -0,0 +1,10 @@
+module.exports = {
+  msgs: {
+    tasks: {
+      childTask: '{1}{child_task: {2}}',
+    }
+  },
+  theme: {
+    child_task: '**{1}**',
+  },
+};
diff --git a/test/fixtures/config/theming/tasks/childTask/gulpfile.js b/test/fixtures/config/theming/tasks/childTask/gulpfile.js
new file mode 100644
index 00000000..b61b53c3
--- /dev/null
+++ b/test/fixtures/config/theming/tasks/childTask/gulpfile.js
@@ -0,0 +1,27 @@
+const { series } = require('gulp');
+
+function taskA(done) {
+  done();
+}
+taskA.description = 'This is task A';
+taskA.flags = {
+  '--abc': 'is a flag for task A',
+};
+
+const taskB = function(done) {
+  done();
+}
+taskB.description = 'This is task B';
+taskB.flags = {
+  '--def': 'is a flag for task B',
+};
+
+const defaults = series(taskA, taskB);
+defaults.description = 'This is default task';
+defaults.flags = {
+  '--ghi': 'is a flag for default task',
+};
+
+exports.default = defaults;
+exports.taskA = taskA;
+exports.taskB = taskB;
diff --git a/test/fixtures/config/theming/tasks/gulpfile/.gulp.json b/test/fixtures/config/theming/tasks/gulpfile/.gulp.json
new file mode 100644
index 00000000..9255c31f
--- /dev/null
+++ b/test/fixtures/config/theming/tasks/gulpfile/.gulp.json
@@ -0,0 +1,10 @@
+{
+  "msgs": {
+    "tasks": {
+      "gulpfile": "{FILE: {1}}"
+    }
+  },
+  "theme": {
+    "FILE": "** {1} **"
+  }
+}
diff --git a/test/fixtures/config/theming/tasks/gulpfile/gulpfile.js b/test/fixtures/config/theming/tasks/gulpfile/gulpfile.js
new file mode 100644
index 00000000..db73dd16
--- /dev/null
+++ b/test/fixtures/config/theming/tasks/gulpfile/gulpfile.js
@@ -0,0 +1,3 @@
+exports.default = function(done) {
+  done();
+}
diff --git a/test/fixtures/config/theming/tasks/gulpfile/remove/.gulp.json b/test/fixtures/config/theming/tasks/gulpfile/remove/.gulp.json
new file mode 100644
index 00000000..2b9fdf1b
--- /dev/null
+++ b/test/fixtures/config/theming/tasks/gulpfile/remove/.gulp.json
@@ -0,0 +1,10 @@
+{
+  "msgs": {
+    "tasks": {
+      "gulpfile": null
+    }
+  },
+  "theme": {
+    "FILE": "** {1} **"
+  }
+}
diff --git a/test/fixtures/config/theming/tasks/gulpfile/remove/gulpfile.js b/test/fixtures/config/theming/tasks/gulpfile/remove/gulpfile.js
new file mode 100644
index 00000000..db73dd16
--- /dev/null
+++ b/test/fixtures/config/theming/tasks/gulpfile/remove/gulpfile.js
@@ -0,0 +1,3 @@
+exports.default = function(done) {
+  done();
+}
diff --git a/test/fixtures/config/theming/tasks/option/.gulp.js b/test/fixtures/config/theming/tasks/option/.gulp.js
new file mode 100644
index 00000000..790af554
--- /dev/null
+++ b/test/fixtures/config/theming/tasks/option/.gulp.js
@@ -0,0 +1,10 @@
+module.exports = {
+  msgs: {
+    tasks: {
+      option: '{1}{OptionName: {2}}{IF:{3}?{4}» {5}}',
+    }
+  },
+  theme: {
+    OptionName: '**{1}**',
+  },
+};
diff --git a/test/fixtures/config/theming/tasks/option/gulpfile.js b/test/fixtures/config/theming/tasks/option/gulpfile.js
new file mode 100644
index 00000000..b61b53c3
--- /dev/null
+++ b/test/fixtures/config/theming/tasks/option/gulpfile.js
@@ -0,0 +1,27 @@
+const { series } = require('gulp');
+
+function taskA(done) {
+  done();
+}
+taskA.description = 'This is task A';
+taskA.flags = {
+  '--abc': 'is a flag for task A',
+};
+
+const taskB = function(done) {
+  done();
+}
+taskB.description = 'This is task B';
+taskB.flags = {
+  '--def': 'is a flag for task B',
+};
+
+const defaults = series(taskA, taskB);
+defaults.description = 'This is default task';
+defaults.flags = {
+  '--ghi': 'is a flag for default task',
+};
+
+exports.default = defaults;
+exports.taskA = taskA;
+exports.taskB = taskB;
diff --git a/test/fixtures/config/theming/tasks/topTask/.gulp.js b/test/fixtures/config/theming/tasks/topTask/.gulp.js
new file mode 100644
index 00000000..b9c00721
--- /dev/null
+++ b/test/fixtures/config/theming/tasks/topTask/.gulp.js
@@ -0,0 +1,10 @@
+module.exports = {
+  msgs: {
+    tasks: {
+      topTask: '{1}{TaskName: {2}}{IF:{3}?{4}{5}}',
+    }
+  },
+  theme: {
+    TaskName: '**{1}**',
+  },
+};
diff --git a/test/fixtures/config/theming/tasks/topTask/gulpfile.js b/test/fixtures/config/theming/tasks/topTask/gulpfile.js
new file mode 100644
index 00000000..b61b53c3
--- /dev/null
+++ b/test/fixtures/config/theming/tasks/topTask/gulpfile.js
@@ -0,0 +1,27 @@
+const { series } = require('gulp');
+
+function taskA(done) {
+  done();
+}
+taskA.description = 'This is task A';
+taskA.flags = {
+  '--abc': 'is a flag for task A',
+};
+
+const taskB = function(done) {
+  done();
+}
+taskB.description = 'This is task B';
+taskB.flags = {
+  '--def': 'is a flag for task B',
+};
+
+const defaults = series(taskA, taskB);
+defaults.description = 'This is default task';
+defaults.flags = {
+  '--ghi': 'is a flag for default task',
+};
+
+exports.default = defaults;
+exports.taskA = taskA;
+exports.taskB = taskB;
diff --git a/test/fixtures/config/theming/tasksJson/gulpfile/.gulp.json b/test/fixtures/config/theming/tasksJson/gulpfile/.gulp.json
new file mode 100644
index 00000000..9255c31f
--- /dev/null
+++ b/test/fixtures/config/theming/tasksJson/gulpfile/.gulp.json
@@ -0,0 +1,10 @@
+{
+  "msgs": {
+    "tasks": {
+      "gulpfile": "{FILE: {1}}"
+    }
+  },
+  "theme": {
+    "FILE": "** {1} **"
+  }
+}
diff --git a/test/fixtures/config/theming/tasksJson/gulpfile/gulpfile.js b/test/fixtures/config/theming/tasksJson/gulpfile/gulpfile.js
new file mode 100644
index 00000000..db73dd16
--- /dev/null
+++ b/test/fixtures/config/theming/tasksJson/gulpfile/gulpfile.js
@@ -0,0 +1,3 @@
+exports.default = function(done) {
+  done();
+}
diff --git a/test/fixtures/config/theming/warn/loaderFailure/.gulp.js b/test/fixtures/config/theming/warn/loaderFailure/.gulp.js
new file mode 100644
index 00000000..9875f824
--- /dev/null
+++ b/test/fixtures/config/theming/warn/loaderFailure/.gulp.js
@@ -0,0 +1,10 @@
+module.exports = {
+  msgs: {
+    warn: {
+      loaderFailure: '{TIMESTAMP}FAIL TO LOAD {ModuleName: {1}}',
+    },
+  },
+  theme: {
+    ModuleName: '**{1}**',
+  },
+};
diff --git a/test/fixtures/config/theming/warn/loaderFailure/gulpfile.coffee b/test/fixtures/config/theming/warn/loaderFailure/gulpfile.coffee
new file mode 100644
index 00000000..1f8b8541
--- /dev/null
+++ b/test/fixtures/config/theming/warn/loaderFailure/gulpfile.coffee
@@ -0,0 +1 @@
+console.log 'hello'
diff --git a/test/fixtures/config/theming/warn/preloadFailure/.gulp.js b/test/fixtures/config/theming/warn/preloadFailure/.gulp.js
new file mode 100644
index 00000000..50e3bcc6
--- /dev/null
+++ b/test/fixtures/config/theming/warn/preloadFailure/.gulp.js
@@ -0,0 +1,10 @@
+module.exports = {
+  msgs: {
+    warn: {
+      preloadFailure: '{TIMESTAMP}FAILED TO PRELOAD {ModuleName: {1}}',
+    },
+  },
+  theme: {
+    ModuleName: '**{1}**',
+  },
+};
diff --git a/test/fixtures/config/theming/warn/preloadFailure/gulpfile.js b/test/fixtures/config/theming/warn/preloadFailure/gulpfile.js
new file mode 100644
index 00000000..db73dd16
--- /dev/null
+++ b/test/fixtures/config/theming/warn/preloadFailure/gulpfile.js
@@ -0,0 +1,3 @@
+exports.default = function(done) {
+  done();
+}
diff --git a/test/fixtures/config/theming/warn/taskNotComplete/.gulp.js b/test/fixtures/config/theming/warn/taskNotComplete/.gulp.js
new file mode 100644
index 00000000..df6bd57f
--- /dev/null
+++ b/test/fixtures/config/theming/warn/taskNotComplete/.gulp.js
@@ -0,0 +1,10 @@
+module.exports = {
+  msgs: {
+    warn: {
+      taskNotComplete: '{TIMESTAMP}TASK {TaskName: {1}} DID NOT COMPLETE',
+    },
+  },
+  theme: {
+    TaskName: '**{1}**',
+  },
+};
diff --git a/test/fixtures/config/theming/warn/taskNotComplete/gulpfile.js b/test/fixtures/config/theming/warn/taskNotComplete/gulpfile.js
new file mode 100644
index 00000000..1e950f9a
--- /dev/null
+++ b/test/fixtures/config/theming/warn/taskNotComplete/gulpfile.js
@@ -0,0 +1,3 @@
+exports.default = function(done) {
+  //done();
+}
diff --git a/test/fixtures/errors/yarn/yarn.lock b/test/fixtures/errors/yarn/yarn.lock
new file mode 100644
index 00000000..e69de29b
diff --git a/test/flags-tasks.js b/test/flags-tasks.js
index 4a1c689f..f43279c0 100644
--- a/test/flags-tasks.js
+++ b/test/flags-tasks.js
@@ -31,7 +31,7 @@ describe('flag: --tasks', function() {
     }
   });
 
-  it('print the task list with description and flags', function(done) {
+  it('prints the task list with description and flags', function(done) {
     var opts = { cwd: baseDir };
     exec(gulp(
       '--tasks',
@@ -50,7 +50,7 @@ describe('flag: --tasks', function() {
     }
   });
 
-  it('print the task list by gulp.task(s).unwrap and gulp.task(s)', function(done) {
+  it('prints the task list by gulp.task(s).unwrap and gulp.task(s)', function(done) {
     var opts = { cwd: baseDir };
     exec(gulp(
       '--tasks',
diff --git a/test/lib/check-task-not-found.js b/test/lib/check-task-not-found.js
new file mode 100644
index 00000000..932c753c
--- /dev/null
+++ b/test/lib/check-task-not-found.js
@@ -0,0 +1,28 @@
+'use strict';
+
+var expect = require('expect');
+var checkTaskNotFound = require('../../lib/versioned/^4.0.0/log/check-task-not-found');
+
+describe('lib: checkTaskNotFound', function() {
+
+  it('Should return target task and similar tasks if both are included in error message', function(done) {
+    var err = new Error('Task never defined: task2 - did you mean? task0, task1');
+    expect(checkTaskNotFound(err)).toEqual({
+      target: 'task2',
+      similar: 'task0, task1',
+    });
+    done();
+  });
+
+  it('Should return only target task if similar tasks is not included in error message', function(done) {
+    var err = new Error('Task never defined: task2');
+    expect(checkTaskNotFound(err)).toEqual({ target: 'task2' });
+    done();
+  });
+
+  it('Should return undefined if error is other', function(done) {
+    var err = new Error('xxx');
+    expect(checkTaskNotFound(err)).toBeUndefined();
+    done();
+  });
+});