feat: support parseForESLint from custom parser

tests/src/core/eslintParser.js

@@ -0,0 +1,7 @@
+module.exports = {
+  parseForESLint: function() {
+    return {
+      ast: {},
+    }
+  },
+}

tests/src/core/parse.js

@@ -9,6 +9,8 @@ describe('parse(content, { settings, ecmaFeatures })', function () {
   const path = getFilename('jsx.js')
   const parseStubParser = require('./parseStubParser')
   const parseStubParserPath = require.resolve('./parseStubParser')
+  const eslintParser = require('./eslintParser')
+  const eslintParserPath = require.resolve('./eslintParser')
   let content
 
   before((done) =>
@@ -43,6 +45,16 @@ describe('parse(content, { settings, ecmaFeatures })', function () {
     expect(parseSpy.args[0][1], 'custom parser to get parserOptions.filePath equal to the full path of the source file').to.have.property('filePath', path)
   })
 
+  it('passes with custom `parseForESLint` parser', function () {
+    const parseForESLintSpy = sinon.spy(eslintParser.parseForESLint)
+    const parseSpy = sinon.spy()
+    eslintParser.parseForESLint = parseForESLintSpy
+    eslintParser.parse = parseSpy
+    parse(path, content, { settings: {}, parserPath: eslintParserPath })
+    expect(parseForESLintSpy.callCount, 'custom `parseForESLint` parser to be called once').to.equal(1)
+    expect(parseSpy.callCount, '`parseForESLint` takes higher priority than `parse`').to.equal(0)
+  })
+
   it('throws on context == null', function () {
     expect(parse.bind(null, path, content, null)).to.throw(Error)
   })

utils/parse.js

@@ -1,4 +1,4 @@
-"use strict"
+'use strict'
 exports.__esModule = true
 
 const moduleRequire = require('./module-require').default
@@ -7,7 +7,6 @@ const extname = require('path').extname
 const log = require('debug')('eslint-plugin-import:parse')
 
 exports.default = function parse(path, content, context) {
-
   if (context == null) throw new Error('need context to parse properly')
 
   let parserOptions = context.parserOptions
@@ -21,7 +20,7 @@ exports.default = function parse(path, content, context) {
 
   // always include comments and tokens (for doc parsing)
   parserOptions.comment = true
-  parserOptions.attachComment = true  // keeping this for backward-compat with  older parsers
+  parserOptions.attachComment = true // keeping this for backward-compat with  older parsers
   parserOptions.tokens = true
 
   // attach node locations
@@ -31,17 +30,35 @@ exports.default = function parse(path, content, context) {
   // provide the `filePath` like eslint itself does, in `parserOptions`
   // https://github.com/eslint/eslint/blob/3ec436ee/lib/linter.js#L637
   parserOptions.filePath = path
-  
+
   // @typescript-eslint/parser will parse the entire project with typechecking if you provide
   // "project" or "projects" in parserOptions. Removing these options means the parser will
   // only parse one file in isolate mode, which is much, much faster.
   // https://github.com/benmosher/eslint-plugin-import/issues/1408#issuecomment-509298962
-  delete parserOptions.project;
-  delete parserOptions.projects;
-  
+  delete parserOptions.project
+  delete parserOptions.projects
+
   // require the parser relative to the main module (i.e., ESLint)
   const parser = moduleRequire(parserPath)
 
+  if (typeof parser.parseForESLint === 'function') {
+    let ast
+    try {
+      ast = parser.parseForESLint(content, parserOptions).ast
+    } catch (e) {
+      //
+    }
+    if (!ast || typeof ast !== 'object') {
+      console.warn(
+        '`parseForESLint` from parser `' +
+          parserPath +
+          '` is invalid and will just be ignored'
+      )
+    } else {
+      return ast
+    }
+  }
+
   return parser.parse(content, parserOptions)
 }