fix: parse titles for function linters

src/makeCmdTasks.js

@@ -4,10 +4,23 @@ const resolveTaskFn = require('./resolveTaskFn')
 
 const debug = require('debug')('lint-staged:make-cmd-tasks')
 
+/**
+ * Get title for linter task. For a function, evaluate by passing single [file].
+ * For strings, return as-is
+ * @param {string|Function} linter
+ */
+const getTitle = linter => {
+  if (typeof linter === 'function') {
+    const resolved = linter(['[file]'])
+    return Array.isArray(resolved) ? resolved[0] : resolved
+  }
+  return linter
+}
+
 /**
  * Creates and returns an array of listr tasks which map to the given commands.
  *
- * @param {Array<string>|string} commands
+ * @param {Array<string|Function>|string|Function} commands
  * @param {Boolean} shell
  * @param {Array<string>} pathsToLint
  * @param {Object} [options]
@@ -18,7 +31,7 @@ module.exports = async function makeCmdTasks(commands, shell, gitDir, pathsToLin
   const lintersArray = Array.isArray(commands) ? commands : [commands]
 
   return lintersArray.map(linter => ({
-    title: linter,
+    title: getTitle(linter),
     task: resolveTaskFn({
       linter,
       shell,

test/makeCmdTasks.spec.js

@@ -52,4 +52,34 @@ describe('makeCmdTasks', () => {
       shell: false
     })
   })
+
+  it('should work with function linter returning a string', async () => {
+    const res = await makeCmdTasks(() => 'test', false, gitDir, ['test.js'])
+    expect(res.length).toBe(1)
+    expect(res[0].title).toEqual('test')
+  })
+
+  it('should work with function linter returning array of string', async () => {
+    const res = await makeCmdTasks(() => ['test', 'test2'], false, gitDir, ['test.js'])
+    expect(res.length).toBe(1)
+    expect(res[0].title).toEqual('test')
+  })
+
+  it('should work with function linter accepting arguments', async () => {
+    const res = await makeCmdTasks(
+      filenames => filenames.map(file => `test ${file}`),
+      false,
+      gitDir,
+      ['test.js']
+    )
+    expect(res.length).toBe(1)
+    expect(res[0].title).toEqual('test [file]')
+  })
+
+  it('should work with array of mixed string and function linters', async () => {
+    const res = await makeCmdTasks([() => 'test', 'test2'], false, gitDir, ['test.js'])
+    expect(res.length).toBe(2)
+    expect(res[0].title).toEqual('test')
+    expect(res[1].title).toEqual('test2')
+  })
 })