From 8b67bd78d769cce7f13370c77b38c2e022eaf6df Mon Sep 17 00:00:00 2001
From: Ali Ijaz Sheikh <ofrobots@google.com>
Date: Mon, 4 Jun 2018 16:58:52 +0300
Subject: [PATCH] fix: use correct lint config for individual files

When invoked with a list of files, linter configuration pertaining to
those files should be preferred rather than the gts default config.
---
 src/lint.ts       | 65 ++++++++++++++++++++++++++++++++---------------
 test/test-lint.ts | 42 +++++++++++++++++++++++++-----
 2 files changed, 80 insertions(+), 27 deletions(-)

diff --git a/src/lint.ts b/src/lint.ts
index 5c24fffb..b26ef826 100644
--- a/src/lint.ts
+++ b/src/lint.ts
@@ -28,28 +28,53 @@ import {Options} from './cli';
  */
 export function lint(
     options: Options, files: string[] = [], fix = false): boolean {
-  const configPath =
-      fs.existsSync(path.join(options.targetRootDir, 'tslint.json')) ?
-      path.resolve(options.targetRootDir, 'tslint.json') :
-      path.resolve(options.gtsRootDir, 'tslint.json');
-
-  const program = createProgram(options);
-  const configuration = Configuration.findConfiguration(configPath, '').results;
-  const linter = new Linter({fix, formatter: 'codeFrame'}, program);
-  const srcFiles = files.length > 0 ? files : Linter.getFileNames(program);
-  srcFiles.forEach(file => {
-    const sourceFile = program.getSourceFile(file);
-    if (sourceFile) {
-      const fileContents = sourceFile.getFullText();
-      linter.lint(file, fileContents, configuration);
+  if (files.length > 0 ) {  // manually provided filenames.
+    const rcs = files.map(file => {
+      // Different config files may apply to each file.
+      const configPath = Configuration.findConfigurationPath(null, file) ||
+          path.join(options.gtsRootDir, 'tslint.json');
+
+      const configuration = Configuration.loadConfigurationFromPath(configPath, '');
+      const source = fs.readFileSync(file, 'utf8');
+
+      const linter = new Linter({fix, formatter: 'codeFrame'});
+      linter.lint(file, source, configuration);
+      const result = linter.getResult();
+      if (result.errorCount || result.warningCount) {
+        options.logger.log(result.output);
+        return false;
+      }
+      return true;
+    });
+
+    return rcs.every(rc => rc);  // if all files succeeded.
+  } else {
+    // Lint the set of files specified by the typescript program config.
+    const program = createProgram(options);
+    files = Linter.getFileNames(program);
+
+    const configPath =
+        fs.existsSync(path.join(options.targetRootDir, 'tslint.json')) ?
+        path.resolve(options.targetRootDir, 'tslint.json') :
+        path.resolve(options.gtsRootDir, 'tslint.json');
+
+    const configuration = Configuration.loadConfigurationFromPath(configPath);
+    const linter = new Linter({fix, formatter: 'codeFrame'}, program);
+
+    files.forEach(file => {
+      const sourceFile = program.getSourceFile(file);
+      if (sourceFile) {
+        const fileContents = sourceFile.getFullText();
+        linter.lint(file, fileContents, configuration);
+      }
+    });
+    const result = linter.getResult();
+    if (result.errorCount || result.warningCount) {
+      options.logger.log(result.output);
+      return false;
     }
-  });
-  const result = linter.getResult();
-  if (result.errorCount || result.warningCount) {
-    options.logger.log(result.output);
-    return false;
+    return true;
   }
-  return true;
 }
 
 export function createProgram(options: Options): ts.Program {
diff --git a/test/test-lint.ts b/test/test-lint.ts
index 0bca9c50..27ce7fb2 100644
--- a/test/test-lint.ts
+++ b/test/test-lint.ts
@@ -135,20 +135,19 @@ test.serial('lint should lint only specified files', async t => {
       });
 });
 
-test.serial('lint should not throw for unrecognized files', async t => {
+test.serial('lint should throw for unrecognized files', async t => {
   await withFixtures(
       {
         'tsconfig.json': JSON.stringify({}),
         'a.ts': GOOD_CODE,
       },
       async () => {
-        lint.lint(OPTIONS, ['z.ts']);
-        t.pass();
+        t.throws(() => {lint.lint(OPTIONS, ['z.ts']);});
       });
 });
 
 test.serial('lint should prefer user config file over default', async t => {
-  const CUSTOM_LINT_CODE = 'const t: Object;';
+  const CUSTOM_LINT_CODE = 'debugger;';
 
   // By defualt the above should fail lint.
   await withFixtures(
@@ -157,8 +156,8 @@ test.serial('lint should prefer user config file over default', async t => {
         'a.ts': CUSTOM_LINT_CODE
       },
       async () => {
-        const okay = lint.lint(OPTIONS);
-        t.is(okay, false);
+        const okay  = lint.lint(OPTIONS);
+        t.false(okay);
       });
 
   // User should be able to override the default config.
@@ -170,8 +169,37 @@ test.serial('lint should prefer user config file over default', async t => {
       },
       async () => {
         const okay = lint.lint(OPTIONS);
-        t.is(okay, true);
+        t.true(okay);
       });
 });
 
+test.serial('lint for specific files should use file-specific config', async t => {
+  const CODE_WITH_PARSEINT = 'parseInt(42);';
+  let logBuffer = '';
+  const optionsWithLog = Object.assign({}, OPTIONS, {
+    logger: {
+      log: (...args: string[]) => {
+        logBuffer += (args.join(' '));
+      },
+      error: nop,
+      dir: nop
+    }
+  });
+  await withFixtures({
+      dira: {
+        'a.ts': CODE_WITH_PARSEINT,
+        // no tslint, so default should apply.
+      },
+      dirb: {
+        'b.ts': CODE_WITH_PARSEINT,
+        'tslint.json': JSON.stringify({})
+      }
+  }, async () => {
+    const okay = lint.lint(optionsWithLog, ['dira/a.ts', 'dirb/b.ts']);
+    t.false(okay);
+    t.regex(logBuffer,    /dira\/a\.ts/);
+    t.notRegex(logBuffer, /dirb\/b\.ts/);
+  });
+});
+
 // TODO: test for when tsconfig.json is missing.