feat/issue-1398: added support for custom configuration

.changeset/thin-onions-attack.md

@@ -0,0 +1,5 @@
+---
+'lint-staged': minor
+---
+
+added support for custom configuration

lib/handleCustomConfig.js

@@ -0,0 +1,40 @@
+import debug from 'debug'
+
+const debugLog = debug('lint-staged:customTask')
+
+import { configurationError } from './messages.js'
+import { makeErr } from './resolveTaskFn.js'
+import { getInitialState } from './state.js'
+
+/**
+ * Handles function configuration and pushes the tasks into the task array
+ *
+ * @param {object} command
+ * @param {Array<string>} files
+ * @param {Array} cmdTasks
+ * @throws {Error} If the function configuration is not valid
+ */
+export const handleCustomConfig = (command, files, cmdTasks) => {
+  debugLog('Handling custom task %o', command)
+  if (typeof command.title === 'string' && typeof command.task === 'function') {
+    const task = async (ctx = getInitialState()) => {
+      try {
+        await command.task(files, ctx)
+      } catch (e) {
+        throw makeErr(command.title, e, ctx)
+      }
+    }
+    cmdTasks.push({
+      title: command.title,
+      task,
+    })
+  } else {
+    throw new Error(
+      configurationError(
+        '[Function]',
+        'Function task should contain `title` and `task` where `title` should be string and `task` should be function.',
+        command
+      )
+    )
+  }
+}

lib/makeCmdTasks.js

@@ -2,6 +2,7 @@ import debug from 'debug'
 
 import { configurationError } from './messages.js'
 import { resolveTaskFn } from './resolveTaskFn.js'
+import { handleCustomConfig } from './handleCustomConfig.js'
 
 const debugLog = debug('lint-staged:makeCmdTasks')
 
@@ -18,33 +19,37 @@ const debugLog = debug('lint-staged:makeCmdTasks')
  */
 export const makeCmdTasks = async ({ commands, cwd, files, topLevelDir, shell, verbose }) => {
   debugLog('Creating listr tasks for commands %o', commands)
-  const commandArray = Array.isArray(commands) ? commands : [commands]
   const cmdTasks = []
-
-  for (const cmd of commandArray) {
-    // command function may return array of commands that already include `stagedFiles`
-    const isFn = typeof cmd === 'function'
-
-    /** Pass copy of file list to prevent mutation by function from config file. */
-    const resolved = isFn ? await cmd([...files]) : cmd
-
-    const resolvedArray = Array.isArray(resolved) ? resolved : [resolved] // Wrap non-array command as array
-
-    for (const command of resolvedArray) {
-      // If the function linter didn't return string | string[]  it won't work
-      // Do the validation here instead of `validateConfig` to skip evaluating the function multiple times
-      if (isFn && typeof command !== 'string') {
-        throw new Error(
-          configurationError(
-            '[Function]',
-            'Function task should return a string or an array of strings',
-            resolved
+  if (!Array.isArray(commands) && typeof commands === 'object') {
+    handleCustomConfig(commands, files, cmdTasks)
+  } else {
+    const commandArray = Array.isArray(commands) ? commands : [commands]
+
+    for (const cmd of commandArray) {
+      // command function may return array of commands that already include `stagedFiles`
+      const isFn = typeof cmd === 'function'
+
+      /** Pass copy of file list to prevent mutation by function from config file. */
+      const resolved = isFn ? await cmd([...files]) : cmd
+
+      const resolvedArray = Array.isArray(resolved) ? resolved : [resolved] // Wrap non-array command as array
+
+      for (const command of resolvedArray) {
+        // If the function linter didn't return string | string[]  it won't work
+        // Do the validation here instead of `validateConfig` to skip evaluating the function multiple times
+        if (isFn && typeof command !== 'string') {
+          throw new Error(
+            configurationError(
+              '[Function]',
+              'Function task should return a string or an array of strings',
+              resolved
+            )
           )
-        )
-      }
+        }
 
-      const task = resolveTaskFn({ command, cwd, files, topLevelDir, isFn, shell, verbose })
-      cmdTasks.push({ title: command, command, task })
+        const task = resolveTaskFn({ command, cwd, files, gitDir, isFn, shell, verbose })
+        cmdTasks.push({ title: command, command, task })
+      }
     }
   }
 

lib/resolveTaskFn.js

@@ -108,7 +108,7 @@ const interruptExecutionOnError = (ctx, execaChildProcess) => {
  * @param {Object} ctx
  * @returns {Error}
  */
-const makeErr = (command, result, ctx) => {
+export const makeErr = (command, result, ctx) => {
   ctx.errors.add(TaskError)
 
   // https://nodejs.org/api/events.html#error-events

lib/validateConfig.js

@@ -70,12 +70,27 @@ export const validateConfigLogic = (config, configPath, logger) => {
       (!Array.isArray(task) ||
         task.some((item) => typeof item !== 'string' && typeof item !== 'function')) &&
       typeof task !== 'string' &&
-      typeof task !== 'function'
+      typeof task !== 'function' &&
+      typeof task !== 'object'
     ) {
       errors.push(
         configurationError(
           pattern,
-          'Should be a string, a function, or an array of strings and functions.',
+          'Should be a string, a function, an object or an array of strings and functions.',
+          task
+        )
+      )
+    }
+
+    if (
+      !Array.isArray(task) &&
+      typeof task === 'object' &&
+      (typeof task.title !== 'string' || typeof task.task !== 'function')
+    ) {
+      errors.push(
+        configurationError(
+          pattern,
+          'Custom task should contain `title` and `task` fields, where `title` should be a string and `task` should be a function.',
           task
         )
       )

test/unit/__snapshots__/validateConfig.spec.js.snap

@@ -5,11 +5,19 @@ exports[`validateConfig should throw and should print validation errors for inva
 
   Invalid value for 'foo': false
 
-  Should be a string, a function, or an array of strings and functions."
+  Should be a string, a function, an object or an array of strings and functions."
 `;
 
 exports[`validateConfig should throw and should print validation errors for invalid config 1 1`] = `"Configuration should be an object or a function"`;
 
+exports[`validateConfig should throw and should print validation errors for invalid object config 1`] = `
+"✖ Validation Error:
+
+  Invalid value for '*.js': { title: 'Running a custom task' }
+
+  Custom task should contain \`title\` and \`task\` fields, where \`title\` should be a string and \`task\` should be a function."
+`;
+
 exports[`validateConfig should throw for empty config 1`] = `"Configuration should not be empty"`;
 
 exports[`validateConfig should throw when detecting deprecated advanced configuration 1`] = `

test/unit/makeCmdTasks.spec.js

@@ -147,4 +147,30 @@ describe('makeCmdTasks', () => {
     /** ...but the original file list was not mutated */
     expect(files).toEqual(['test.js'])
   })
+
+  it('should work with function task returning an object with title and task', async () => {
+    const res = await makeCmdTasks({
+      commands: { title: 'test', task: () => {} },
+      gitDir,
+      files: ['test.js'],
+    })
+    expect(res.length).toBe(1)
+    expect(res[0].title).toEqual('test')
+    expect(typeof res[0].task).toBe('function')
+  })
+
+  it('should throw error when function task fails', async () => {
+    const failingTask = () => {
+      throw new Error('Task failed')
+    }
+
+    const res = await makeCmdTasks({
+      commands: { title: 'test', task: failingTask },
+      gitDir,
+      files: ['test.js'],
+    })
+
+    const [linter] = res
+    await expect(linter.task()).rejects.toThrow()
+  })
 })

test/unit/validateConfig.spec.js

@@ -25,6 +25,30 @@ describe('validateConfig', () => {
     expect(() => validateConfig(invalidConfig, configPath, logger)).toThrowErrorMatchingSnapshot()
   })
 
+  it('should throw and should print validation errors for invalid object config', () => {
+    const invalidConfig = {
+      '*.js': {
+        title: 'Running a custom task',
+      },
+    }
+
+    expect(() => validateConfig(invalidConfig, configPath, logger)).toThrowErrorMatchingSnapshot()
+  })
+
+  it('should not throw and should print nothing for valid object config', () => {
+    const validObjectConfig = {
+      '*.js': {
+        title: 'Running a custom task',
+        task: async (files) => {
+          console.log(files)
+        },
+      },
+    }
+
+    expect(() => validateConfig(validObjectConfig, configPath, logger)).not.toThrow()
+    expect(logger.printHistory()).toEqual('')
+  })
+
   it('should throw for empty config', () => {
     expect(() => validateConfig({}, configPath, logger)).toThrowErrorMatchingSnapshot()
   })