Add espree parser (#9000)

Co-authored-by: Chris Brody <chris.brody+brodybits@gmail.com>

changelog_unreleased/javascript/pr-9000.md

@@ -0,0 +1,5 @@
+#### Add `espree` parser (#9000 by @fisker)
+
+A new value for the `parser` option has been added: [`espree`](https://github.com/eslint/espree) - which is the [`ESLint`](https://github.com/eslint/eslint) default parser.
+
+Note that `espree` only works for [ECMAScript Finished Proposals](https://github.com/tc39/proposals/blob/master/finished-proposals.md), and is stricter than the `babel` parser.

cspell.json

@@ -105,6 +105,7 @@
         "esbenp",
         "eslintignore",
         "eslump",
+        "espree",
         "esproposal",
         "estree",
         "esutils",

docs/options.md

@@ -211,6 +211,7 @@ Valid options:
 - `"babel-ts"` (similar to `"typescript"` but uses Babel and its TypeScript plugin) _First available in v2.0.0_
 - `"flow"` (via [flow-parser](https://github.com/facebook/flow/tree/master/src/parser))
 - `"typescript"` (via [@typescript-eslint/typescript-estree](https://github.com/typescript-eslint/typescript-eslint)) _First available in v1.4.0_
+- `"espree"` (via [espree](https://github.com/eslint/espree)) _First available in v2.2.0_
 - `"css"` (via [postcss](https://github.com/postcss/postcss)) _First available in v1.7.1_
 - `"scss"` (via [postcss-scss](https://github.com/postcss/postcss-scss)) _First available in v1.7.1_
 - `"less"` (via [postcss-less](https://github.com/shellscape/postcss-less) _First available in v1.7.1_

package.json

@@ -38,6 +38,7 @@
     "editorconfig": "0.15.3",
     "editorconfig-to-prettier": "0.2.0",
     "escape-string-regexp": "4.0.0",
+    "espree": "7.3.0",
     "esutils": "2.0.3",
     "fast-glob": "3.2.4",
     "fast-json-stable-stringify": "2.1.0",

scripts/build/config.js

@@ -42,6 +42,9 @@ const parsers = [
       'typeof globalThis === "object"': "true",
     },
   },
+  {
+    input: "src/language-js/parser-espree.js",
+  },
   {
     input: "src/language-js/parser-angular.js",
   },

src/language-js/clean.js

@@ -27,6 +27,8 @@ function clean(ast, newObj, parent) {
     if (newObj.value) {
       newObj.value = newObj.value.toLowerCase();
     }
+  }
+  if (ast.type === "BigIntLiteral" || ast.type === "Literal") {
     if (newObj.bigint) {
       newObj.bigint = newObj.bigint.toLowerCase();
     }

src/language-js/comments.js

@@ -991,7 +991,9 @@ function getCommentChildNodes(node, options) {
   //       }
   //     }
   if (
-    (options.parser === "typescript" || options.parser === "flow") &&
+    (options.parser === "typescript" ||
+      options.parser === "flow" ||
+      options.parser === "espree") &&
     node.type === "MethodDefinition" &&
     node.value &&
     node.value.type === "FunctionExpression" &&

src/language-js/index.js

@@ -10,7 +10,14 @@ const languages = [
     require("linguist-languages/data/JavaScript.json"),
     (data) => ({
       since: "0.0.0",
-      parsers: ["babel", "babel-flow", "babel-ts", "flow", "typescript"],
+      parsers: [
+        "babel",
+        "espree",
+        "babel-flow",
+        "babel-ts",
+        "flow",
+        "typescript",
+      ],
       vscodeLanguageIds: ["javascript", "mongo"],
       extensions: [
         ...data.extensions,
@@ -31,7 +38,14 @@ const languages = [
   })),
   createLanguage(require("linguist-languages/data/JSX.json"), () => ({
     since: "0.0.0",
-    parsers: ["babel", "babel-flow", "babel-ts", "flow", "typescript"],
+    parsers: [
+      "babel",
+      "babel-flow",
+      "babel-ts",
+      "flow",
+      "typescript",
+      "espree",
+    ],
     vscodeLanguageIds: ["javascriptreact"],
   })),
   createLanguage(require("linguist-languages/data/TypeScript.json"), () => ({
@@ -132,6 +146,10 @@ const parsers = {
   get __ng_directive() {
     return require("./parser-angular").parsers.__ng_directive;
   },
+  // JS - espree
+  get espree() {
+    return require("./parser-espree").parsers.espree;
+  },
 };
 
 module.exports = {

src/language-js/parser-espree.js

@@ -0,0 +1,59 @@
+"use strict";
+const { getShebang } = require("../common/util");
+const createError = require("../common/parser-create-error");
+const { hasPragma } = require("./pragma");
+const { locStart, locEnd } = require("./loc");
+const postprocess = require("./postprocess");
+
+const espreeOptions = {
+  range: true,
+  loc: true,
+  comment: true,
+  tokens: true,
+  sourceType: "module",
+  ecmaFeatures: {
+    jsx: true,
+    globalReturn: true,
+    impliedStrict: false,
+  },
+};
+
+function parse(originalText, parsers, options) {
+  const { parse, latestEcmaVersion } = require("espree");
+  espreeOptions.ecmaVersion = latestEcmaVersion;
+
+  // Replace shebang with space
+  const shebang = getShebang(originalText);
+  const text = shebang
+    ? " ".repeat(shebang.length) + originalText.slice(shebang.length)
+    : originalText;
+
+  let ast;
+
+  try {
+    ast = parse(text, espreeOptions);
+  } catch (moduleError) {
+    try {
+      ast = parse(text, { ...espreeOptions, sourceType: "script" });
+    } catch (scriptError) {
+      // throw the error for `module` parsing
+
+      /* istanbul ignore next */
+      if (typeof moduleError.lineNumber === "undefined") {
+        throw moduleError;
+      }
+
+      throw createError(moduleError.message, {
+        start: { line: moduleError.lineNumber, column: moduleError.column },
+      });
+    }
+  }
+
+  return postprocess(ast, { ...options, originalText });
+}
+
+module.exports = {
+  parsers: {
+    espree: { parse, astFormat: "estree", hasPragma, locStart, locEnd },
+  },
+};

src/language-js/postprocess.js

@@ -9,12 +9,20 @@ const { composeLoc, locStart, locEnd } = require("./loc");
 const { isTypeCastComment } = require("./comments");
 
 function postprocess(ast, options) {
-  if (options.parser === "typescript" || options.parser === "flow") {
+  if (
+    options.parser === "typescript" ||
+    options.parser === "flow" ||
+    options.parser === "espree"
+  ) {
     includeShebang(ast, options);
   }
 
   // Keep Babel's non-standard ParenthesizedExpression nodes only if they have Closure-style type cast comments.
-  if (options.parser !== "typescript" && options.parser !== "flow") {
+  if (
+    options.parser !== "typescript" &&
+    options.parser !== "flow" &&
+    options.parser !== "espree"
+  ) {
     const startOffsetsOfTypeCastedNodes = new Set();
 
     // Comments might be attached not directly to ParenthesizedExpression but to its ancestor.
@@ -48,6 +56,10 @@ function postprocess(ast, options) {
 
   ast = visitNode(ast, (node) => {
     switch (node.type) {
+      // Espree
+      case "ChainExpression": {
+        return transformChainExpression(node.expression);
+      }
       case "LogicalExpression": {
         // We remove unneeded parens around same-operator LogicalExpressions
         if (isUnbalancedLogicalTree(node)) {
@@ -126,6 +138,21 @@ function postprocess(ast, options) {
   }
 }
 
+// This is a workaround to transform `ChainExpression` from `espree` into
+// `babel` shape AST, we should do the opposite, since `ChainExpression` is the
+// standard `estree` AST for `optional chaining`
+// https://github.com/estree/estree/blob/master/es2020.md
+function transformChainExpression(node) {
+  if (node.type === "CallExpression") {
+    node.type = "OptionalCallExpression";
+    node.callee = transformChainExpression(node.callee);
+  } else if (node.type === "MemberExpression") {
+    node.type = "OptionalMemberExpression";
+    node.object = transformChainExpression(node.object);
+  }
+  return node;
+}
+
 function visitNode(node, fn) {
   let entries;
 

src/language-js/utils.js

@@ -927,7 +927,7 @@ function returnArgumentHasLeadingComment(options, argument) {
 //
 // Angular does not support unquoted numbers in expressions.
 //
-// So we play it safe and only unquote numbers for the "babel" parser.
+// So we play it safe and only unquote numbers for the JavaScript parsers.
 // (Vue supports unquoted numbers in expressions, but let’s keep it simple.)
 //
 // Identifiers can be unquoted in more circumstances, though.
@@ -945,7 +945,7 @@ function isStringPropSafeToUnquote(node, options) {
       )) ||
       (isSimpleNumber(node.key.value) &&
         String(Number(node.key.value)) === node.key.value &&
-        options.parser === "babel"))
+        (options.parser === "babel" || options.parser === "espree")))
   );
 }
 

src/main/core-options.js

@@ -129,6 +129,7 @@ const options = {
       { value: "babel-flow", since: "1.16.0", description: "Flow" },
       { value: "babel-ts", since: "2.0.0", description: "TypeScript" },
       { value: "typescript", since: "1.4.0", description: "TypeScript" },
+      { value: "espree", since: "2.2.0", description: "JavaScript" },
       { value: "css", since: "1.7.1", description: "CSS" },
       { value: "less", since: "1.7.1", description: "Less" },
       { value: "scss", since: "1.7.1", description: "SCSS" },

src/main/range-util.js

@@ -119,6 +119,7 @@ function isSourceElement(opts, node) {
     case "babel-flow":
     case "babel-ts":
     case "typescript":
+    case "espree":
       return isJsSourceElement(node.type);
     case "json":
       return jsonSourceElements.has(node.type);

tests/js/arrow-call/__snapshots__/jsfmt.spec.js.snap

@@ -45,11 +45,6 @@ func(
     veryLoooooooooooooooongName.something()
 );
 
-const composition = (ViewComponent, ContainerComponent) =>
-  class extends React.Component {
-    static propTypes = {};
-  };
-
 promise.then(result => result.veryLongVariable.veryLongPropertyName > someOtherVariable ? "ok" : "fail");
 
 =====================================output=====================================
@@ -97,11 +92,6 @@ func(
     veryLoooooooooooooooongName.something()
 );
 
-const composition = (ViewComponent, ContainerComponent) =>
-  class extends React.Component {
-    static propTypes = {};
-  };
-
 promise.then((result) =>
   result.veryLongVariable.veryLongPropertyName > someOtherVariable
     ? "ok"
@@ -156,11 +146,6 @@ func(
     veryLoooooooooooooooongName.something()
 );
 
-const composition = (ViewComponent, ContainerComponent) =>
-  class extends React.Component {
-    static propTypes = {};
-  };
-
 promise.then(result => result.veryLongVariable.veryLongPropertyName > someOtherVariable ? "ok" : "fail");
 
 =====================================output=====================================
@@ -208,11 +193,6 @@ func(
     veryLoooooooooooooooongName.something(),
 );
 
-const composition = (ViewComponent, ContainerComponent) =>
-  class extends React.Component {
-    static propTypes = {};
-  };
-
 promise.then((result) =>
   result.veryLongVariable.veryLongPropertyName > someOtherVariable
     ? "ok"
@@ -266,11 +246,6 @@ func(
     veryLoooooooooooooooongName.something()
 );
 
-const composition = (ViewComponent, ContainerComponent) =>
-  class extends React.Component {
-    static propTypes = {};
-  };
-
 promise.then(result => result.veryLongVariable.veryLongPropertyName > someOtherVariable ? "ok" : "fail");
 
 =====================================output=====================================
@@ -318,11 +293,6 @@ func(
     veryLoooooooooooooooongName.something()
 );
 
-const composition = (ViewComponent, ContainerComponent) =>
-  class extends React.Component {
-    static propTypes = {};
-  };
-
 promise.then((result) =>
   result.veryLongVariable.veryLongPropertyName > someOtherVariable
     ? "ok"
@@ -331,3 +301,65 @@ promise.then((result) =>
 
 ================================================================================
 `;
+
+exports[`class-property.js - {"arrowParens":"always"} format 1`] = `
+====================================options=====================================
+arrowParens: "always"
+parsers: ["babel", "flow", "typescript"]
+printWidth: 80
+                                                                                | printWidth
+=====================================input======================================
+const composition = (ViewComponent, ContainerComponent) =>
+  class extends React.Component {
+    static propTypes = {};
+  };
+
+=====================================output=====================================
+const composition = (ViewComponent, ContainerComponent) =>
+  class extends React.Component {
+    static propTypes = {};
+  };
+
+================================================================================
+`;
+
+exports[`class-property.js - {"trailingComma":"all"} format 1`] = `
+====================================options=====================================
+parsers: ["babel", "flow", "typescript"]
+printWidth: 80
+trailingComma: "all"
+                                                                                | printWidth
+=====================================input======================================
+const composition = (ViewComponent, ContainerComponent) =>
+  class extends React.Component {
+    static propTypes = {};
+  };
+
+=====================================output=====================================
+const composition = (ViewComponent, ContainerComponent) =>
+  class extends React.Component {
+    static propTypes = {};
+  };
+
+================================================================================
+`;
+
+exports[`class-property.js format 1`] = `
+====================================options=====================================
+parsers: ["babel", "flow", "typescript"]
+printWidth: 80
+                                                                                | printWidth
+=====================================input======================================
+const composition = (ViewComponent, ContainerComponent) =>
+  class extends React.Component {
+    static propTypes = {};
+  };
+
+=====================================output=====================================
+const composition = (ViewComponent, ContainerComponent) =>
+  class extends React.Component {
+    static propTypes = {};
+  };
+
+================================================================================
+`;

tests/js/arrow-call/arrow_call.js

@@ -36,9 +36,4 @@ func(
     veryLoooooooooooooooongName.something()
 );
 
-const composition = (ViewComponent, ContainerComponent) =>
-  class extends React.Component {
-    static propTypes = {};
-  };
-
 promise.then(result => result.veryLongVariable.veryLongPropertyName > someOtherVariable ? "ok" : "fail");

tests/js/arrow-call/class-property.js

@@ -0,0 +1,4 @@
+const composition = (ViewComponent, ContainerComponent) =>
+  class extends React.Component {
+    static propTypes = {};
+  };

tests/js/arrow-call/jsfmt.spec.js

@@ -1,7 +1,15 @@
-run_spec(__dirname, ["babel", "flow", "typescript"]);
+const errors = {
+  espree: ["class-property.js"],
+};
+
+run_spec(__dirname, ["babel", "flow", "typescript"], {
+  errors,
+});
 run_spec(__dirname, ["babel", "flow", "typescript"], {
   trailingComma: "all",
+  errors,
 });
 run_spec(__dirname, ["babel", "flow", "typescript"], {
   arrowParens: "always",
+  errors,
 });

tests/js/arrows-bind/jsfmt.spec.js

@@ -1 +1 @@
-run_spec(__dirname, ["babel"]);
+run_spec(__dirname, ["babel"], { errors: { espree: true } });

tests/js/arrows/newline-before-arrow/jsfmt.spec.js

@@ -1 +1,3 @@
-run_spec(__dirname, ["babel"]);
+run_spec(__dirname, ["babel"], {
+  errors: { espree: ["newline-before-arrow.js"] },
+});

tests/js/babel-plugins/jsfmt.spec.js

@@ -1,4 +1,31 @@
 // Only testing babel parsing
 // Do not add extra parsers here
 
-run_spec(__dirname, ["babel", "babel-ts", "babel-flow"]);
+run_spec(__dirname, ["babel", "babel-ts", "babel-flow"], {
+  errors: {
+    espree: [
+      "class-properties.js",
+      "decimal.js",
+      "decorators.js",
+      "do-expressions.js",
+      "export-default-from.js",
+      "flow.js",
+      "function-bind.js",
+      "function-sent.js",
+      "module-attributes-dynamic.js",
+      "module-attributes-static.js",
+      "partial-application.js",
+      "pipeline-operator-fsharp.js",
+      "pipeline-operator-minimal.js",
+      "pipeline-operator-smart.js",
+      "private-fields-in-in.js",
+      "private-methods.js",
+      "record-tuple-record.js",
+      "record-tuple-tuple.js",
+      "throw-expressions.js",
+      "typescript.js",
+      "v8intrinsic.js",
+      "optional-chaining.js",
+    ],
+  },
+});

tests/js/bind-expressions/jsfmt.spec.js

@@ -1,2 +1,2 @@
-run_spec(__dirname, ["babel"]);
-run_spec(__dirname, ["babel"], { semi: false });
+run_spec(__dirname, ["babel"], { errors: { espree: true } });
+run_spec(__dirname, ["babel"], { semi: false, errors: { espree: true } });

tests/js/class-comment/jsfmt.spec.js

@@ -1 +1,5 @@
-run_spec(__dirname, ["babel", "flow", "typescript"]);
+run_spec(__dirname, ["babel", "flow", "typescript"], {
+  errors: {
+    espree: ["class-property.js"],
+  },
+});

tests/js/classes-private-fields/jsfmt.spec.js

@@ -1,2 +1,2 @@
-run_spec(__dirname, ["babel"]);
-run_spec(__dirname, ["babel"], { semi: false });
+run_spec(__dirname, ["babel"], { errors: { espree: true } });
+run_spec(__dirname, ["babel"], { semi: false, errors: { espree: true } });

tests/js/classes/jsfmt.spec.js

@@ -1 +1,3 @@
-run_spec(__dirname, ["babel", "flow", "typescript"]);
+run_spec(__dirname, ["babel", "flow", "typescript"], {
+  errors: { espree: ["property.js"] },
+});

tests/js/classes/top-level-super/jsfmt.spec.js

@@ -1 +1 @@
-run_spec(__dirname, ["babel", "typescript"]);
+run_spec(__dirname, ["babel", "typescript"], { errors: { espree: true } });

tests/js/comments-pipeline-own-line/jsfmt.spec.js

@@ -1 +1 @@
-run_spec(__dirname, ["babel"]);
+run_spec(__dirname, ["babel"], { errors: { espree: true } });

tests/js/decorator-comments/jsfmt.spec.js

@@ -1 +1 @@
-run_spec(__dirname, ["babel", "typescript"]);
+run_spec(__dirname, ["babel", "typescript"], { errors: { espree: true } });

tests/js/decorators-export/jsfmt.spec.js

@@ -1,2 +1,2 @@
 // TypeScript and Flow don't accept decorator after export
-run_spec(__dirname, ["babel"]);
+run_spec(__dirname, ["babel"], { errors: { espree: true } });

tests/js/decorators/jsfmt.spec.js

@@ -1 +1 @@
-run_spec(__dirname, ["babel"]);
+run_spec(__dirname, ["babel"], { errors: { espree: true } });

tests/js/do/jsfmt.spec.js

@@ -1 +1 @@
-run_spec(__dirname, ["babel"]);
+run_spec(__dirname, ["babel"], { errors: { espree: true } });

tests/js/empty-paren-comment/jsfmt.spec.js

@@ -1 +1,3 @@
-run_spec(__dirname, ["babel", "flow", "typescript"]);
+run_spec(__dirname, ["babel", "flow", "typescript"], {
+  errors: { espree: ["class-property.js"] },
+});

tests/js/export-default/escaped/jsfmt.spec.js

@@ -1 +1,3 @@
-run_spec(__dirname, ["babel"]);
+run_spec(__dirname, ["babel"], {
+  errors: { espree: true },
+});

tests/js/export-extension/jsfmt.spec.js

@@ -1 +1 @@
-run_spec(__dirname, ["babel"]);
+run_spec(__dirname, ["babel"], { errors: { espree: true } });

tests/js/exports/jsfmt.spec.js

@@ -1 +1 @@
-run_spec(__dirname, ["babel"]);
+run_spec(__dirname, ["babel"], { errors: { espree: true } });

tests/js/functional-composition/jsfmt.spec.js

@@ -1 +1,5 @@
-run_spec(__dirname, ["babel", "flow", "typescript"]);
+run_spec(__dirname, ["babel", "flow", "typescript"], {
+  errors: {
+    espree: [],
+  },
+});

tests/js/invalid-code/jsfmt.spec.js

@@ -1 +1 @@
-run_spec(__dirname, ["babel"]);
+run_spec(__dirname, ["babel"], { errors: { espree: true } });

tests/js/literal/jsfmt.spec.js

@@ -1,2 +1,2 @@
 // flow-parser@0.38.0 fails to parse `1.e1`, so use babel here.
-run_spec(__dirname, ["babel", "typescript"]);
+run_spec(__dirname, ["babel", "typescript"], { errors: { espree: true } });

tests/js/logical-assignment/__snapshots__/jsfmt.spec.js.snap

@@ -1,5 +1,19 @@
 // Jest Snapshot v1, https://goo.gl/fbAQLP
 
+exports[`invalid.js format 1`] = `
+====================================options=====================================
+parsers: ["babel", "typescript"]
+printWidth: 80
+                                                                                | printWidth
+=====================================input======================================
+c.foo.bar().baz ??= result.foo.bar().baz(a.baz) &&= result.baz;
+
+=====================================output=====================================
+c.foo.bar().baz ??= result.foo.bar().baz(a.baz) &&= result.baz;
+
+================================================================================
+`;
+
 exports[`logical-assignment.js format 1`] = `
 ====================================options=====================================
 parsers: ["babel", "typescript"]
@@ -26,7 +40,6 @@ c.foo["baz"] ??= result.foo.baz;
 
 a.foo.bar().baz &&= result.foo.bar().baz;
 b.foo.bar().baz ||= result.foo.bar().baz;
-c.foo.bar().baz ??= result.foo.bar().baz(a.baz) &&= result.baz;
 b.baz ||= result.baz;
 c.baz ??= result.baz;
 
@@ -83,7 +96,6 @@ c.foo["baz"] ??= result.foo.baz;
 
 a.foo.bar().baz &&= result.foo.bar().baz;
 b.foo.bar().baz ||= result.foo.bar().baz;
-c.foo.bar().baz ??= result.foo.bar().baz(a.baz) &&= result.baz;
 b.baz ||= result.baz;
 c.baz ??= result.baz;
 

tests/js/logical-assignment/invalid.js

@@ -0,0 +1 @@
+c.foo.bar().baz ??= result.foo.bar().baz(a.baz) &&= result.baz;

tests/js/logical-assignment/jsfmt.spec.js

@@ -1 +1,3 @@
-run_spec(__dirname, ["babel", "typescript"]);
+run_spec(__dirname, ["babel", "typescript"], {
+  errors: { espree: ["invalid.js"] },
+});

tests/js/logical-assignment/logical-assignment.js

@@ -18,7 +18,6 @@ c.foo["baz"] ??= result.foo.baz;
 
 a.foo.bar().baz &&= result.foo.bar().baz;
 b.foo.bar().baz ||= result.foo.bar().baz;
-c.foo.bar().baz ??= result.foo.bar().baz(a.baz) &&= result.baz;
 b.baz ||= result.baz;
 c.baz ??= result.baz;
 

tests/js/module-attributes/jsfmt.spec.js

@@ -1 +1 @@
-run_spec(__dirname, ["babel"]);
+run_spec(__dirname, ["babel"], { errors: { espree: true } });

tests/js/multiparser-css/__snapshots__/jsfmt.spec.js.snap

@@ -250,7 +250,7 @@ const Steps = styled.div\`
   }
 \`;
 
-const Steps = styled.div\`
+const Steps2 = styled.div\`
   @media (min-width: \${breakpoints.lg}) {
     \${Step} {
       margin-bottom: 90px;
@@ -288,7 +288,7 @@ const Steps = styled.div\`
   }
 \`;
 
-const Steps = styled.div\`
+const Steps2 = styled.div\`
   @media (min-width: \${breakpoints.lg}) {
     \${Step} {
       margin-bottom: 90px;

tests/js/multiparser-css/issue-5961.js

@@ -4,7 +4,7 @@ const Steps = styled.div`
   }
 `;
 
-const Steps = styled.div`
+const Steps2 = styled.div`
   @media (min-width: ${breakpoints.lg}) {
     ${Step} {
       margin-bottom: 90px;

tests/js/no-semi-babylon-extensions/jsfmt.spec.js

@@ -1,2 +1,2 @@
-run_spec(__dirname, ["babel"]);
-run_spec(__dirname, ["babel"], { semi: false });
+run_spec(__dirname, ["babel"], { errors: { espree: true } });
+run_spec(__dirname, ["babel"], { semi: false, errors: { espree: true } });

tests/js/no-semi/jsfmt.spec.js

@@ -1,2 +1,4 @@
-run_spec(__dirname, ["babel", "flow"]);
-run_spec(__dirname, ["babel", "flow"], { semi: false });
+const errors = { espree: ["class.js"] };
+
+run_spec(__dirname, ["babel", "flow"], { errors });
+run_spec(__dirname, ["babel", "flow"], { semi: false, errors });

tests/js/object-property-comment/jsfmt.spec.js

@@ -1 +1,3 @@
-run_spec(__dirname, ["babel", "flow"]);
+run_spec(__dirname, ["babel", "flow"], {
+  errors: { espree: ["comment.js"] },
+});

tests/js/objects/jsfmt.spec.js

@@ -1 +1,3 @@
-run_spec(__dirname, ["babel"]);
+run_spec(__dirname, ["babel"], {
+  errors: { espree: ["expression.js", "invalid-accessor-generator.js"] },
+});

tests/js/partial-application/jsfmt.spec.js

@@ -1 +1 @@
-run_spec(__dirname, ["babel"]);
+run_spec(__dirname, ["babel"], { errors: { espree: true } });

tests/js/pipeline-operator/jsfmt.spec.js

@@ -1 +1 @@
-run_spec(__dirname, ["babel"]);
+run_spec(__dirname, ["babel"], { errors: { espree: true } });

tests/js/private-in/jsfmt.spec.js

@@ -1 +1 @@
-run_spec(__dirname, ["babel"]);
+run_spec(__dirname, ["babel"], { errors: { espree: true } });

tests/js/quote-props/jsfmt.spec.js

@@ -1,16 +1,22 @@
+const errors = { espree: ["classes.js"] };
+
 run_spec(__dirname, ["babel"], {
   quoteProps: "as-needed",
+  errors,
 });
 
 run_spec(__dirname, ["babel"], {
   quoteProps: "preserve",
+  errors,
 });
 
 run_spec(__dirname, ["babel"], {
   quoteProps: "consistent",
+  errors,
 });
 
 run_spec(__dirname, ["babel"], {
   quoteProps: "consistent",
   singleQuote: true,
+  errors,
 });

tests/js/record/jsfmt.spec.js

@@ -1 +1 @@
-run_spec(__dirname, ["babel"]);
+run_spec(__dirname, ["babel"], { errors: { espree: true } });

tests/js/rest/jsfmt.spec.js

@@ -1 +1,4 @@
-run_spec(__dirname, ["babel", "flow"], { trailingComma: "all" });
+run_spec(__dirname, ["babel", "flow"], {
+  trailingComma: "all",
+  errors: { espree: true },
+});

tests/js/test-declarations/jsfmt.spec.js

@@ -1,2 +1,4 @@
 run_spec(__dirname, ["babel", "flow", "typescript"]);
-run_spec(__dirname, ["babel", "flow", "typescript"], { arrowParens: "avoid" });
+run_spec(__dirname, ["babel", "flow", "typescript"], {
+  arrowParens: "avoid",
+});

tests/js/throw_expressions/jsfmt.spec.js

@@ -1 +1 @@
-run_spec(__dirname, ["babel"]);
+run_spec(__dirname, ["babel"], { errors: { espree: true } });

tests/js/top-level-await/jsfmt.spec.js

@@ -1 +1 @@
-run_spec(__dirname, ["babel", "typescript"]);
+run_spec(__dirname, ["babel", "typescript"], { errors: { espree: true } });

tests/js/trailing-whitespace/jsfmt.spec.js

@@ -1 +1,3 @@
-run_spec(__dirname, ["babel", "flow", "typescript"]);
+run_spec(__dirname, ["babel", "flow", "typescript"], {
+  errors: { espree: true },
+});

tests/js/tuple/jsfmt.spec.js

@@ -1 +1 @@
-run_spec(__dirname, ["babel"]);
+run_spec(__dirname, ["babel"], { errors: { espree: true } });

tests/js/v8_intrinsic/jsfmt.spec.js

@@ -1 +1 @@
-run_spec(__dirname, ["babel"]);
+run_spec(__dirname, ["babel"], { errors: { espree: true } });

tests_config/run_spec.js

@@ -48,6 +48,13 @@ const unstableTests = new Map(
   })
 );
 
+const espreeDisabledTests = new Set(
+  [
+    // These tests only work for `babel`
+    "comments-closure-typecast",
+  ].map((directory) => path.join(__dirname, "../tests/js", directory))
+);
+
 const isUnstable = (filename, options) => {
   const testFunction = unstableTests.get(filename);
 
@@ -58,18 +65,14 @@ const isUnstable = (filename, options) => {
   return testFunction(options);
 };
 
+// TODO: refactor `disableBabelTS` option to use `errors`
 const shouldThrowOnFormat = (filename, options) => {
-  if (options.parser !== "babel-ts") {
-    return false;
-  }
+  const { errors = {}, disableBabelTS } = options;
+  errors["babel-ts"] = disableBabelTS;
 
-  const { disableBabelTS } = options;
+  const files = errors[options.parser];
 
-  if (disableBabelTS === true) {
-    return true;
-  }
-
-  if (Array.isArray(disableBabelTS) && disableBabelTS.includes(filename)) {
+  if (files === true || (Array.isArray(files) && files.includes(filename))) {
     return true;
   }
 
@@ -77,7 +80,9 @@ const shouldThrowOnFormat = (filename, options) => {
 };
 
 const isTestDirectory = (dirname, name) =>
-  dirname.startsWith(path.join(__dirname, "../tests", name));
+  (dirname + path.sep).startsWith(
+    path.join(__dirname, "../tests", name) + path.sep
+  );
 
 function runSpec(fixtures, parsers, options) {
   let { dirname, snippets = [] } =
@@ -144,6 +149,15 @@ function runSpec(fixtures, parsers, options) {
     allParsers.push("babel-ts");
   }
 
+  if (
+    parsers.includes("babel") &&
+    !parsers.includes("espree") &&
+    isTestDirectory(dirname, "js") &&
+    !espreeDisabledTests.has(dirname)
+  ) {
+    allParsers.push("espree");
+  }
+
   const stringifiedOptions = stringifyOptionsForTitle(options);
 
   for (const { name, filename, code, output } of [...files, ...snippets]) {

tests_config/utils/compose-options-for-snapshot.js

@@ -6,6 +6,7 @@ function composeOptionsForSnapshot(baseOptions, parsers) {
     plugins,
     filepath,
     parser,
+    errors,
 
     ...snapshotOptions
   } = baseOptions;

tests_config/utils/stringify-options-for-title.js

@@ -2,7 +2,7 @@
 
 function stringifyOptions(options) {
   const string = JSON.stringify(options || {}, (key, value) =>
-    key === "disableBabelTS" || key === "plugins"
+    key === "disableBabelTS" || key === "plugins" || key === "errors"
       ? undefined
       : value === Infinity
       ? "Infinity"

tests_integration/__tests__/__snapshots__/early-exit.js.snap

@@ -84,7 +84,7 @@ Format options:
                            Defaults to false.
   --jsx-single-quote       Use single quotes in JSX.
                            Defaults to false.
-  --parser <flow|babel|babel-flow|babel-ts|typescript|css|less|scss|json|json5|json-stringify|graphql|markdown|mdx|vue|yaml|html|angular|lwc>
+  --parser <flow|babel|babel-flow|babel-ts|typescript|espree|css|less|scss|json|json5|json-stringify|graphql|markdown|mdx|vue|yaml|html|angular|lwc>
                            Which parser to use.
   --print-width <int>      The line length where Prettier will try wrap.
                            Defaults to 80.
@@ -180,7 +180,7 @@ exports[`show warning with --help not-found (typo) (stderr) 1`] = `
 `;
 
 exports[`show warning with --help not-found (typo) (stdout) 1`] = `
-"--parser <flow|babel|babel-flow|babel-ts|typescript|css|less|scss|json|json5|json-stringify|graphql|markdown|mdx|vue|yaml|html|angular|lwc>
+"--parser <flow|babel|babel-flow|babel-ts|typescript|espree|css|less|scss|json|json5|json-stringify|graphql|markdown|mdx|vue|yaml|html|angular|lwc>
 
   Which parser to use.
 
@@ -191,6 +191,7 @@ Valid options:
   babel-flow       Flow
   babel-ts         TypeScript
   typescript       TypeScript
+  espree           JavaScript
   css              CSS
   less             Less
   scss             SCSS
@@ -244,7 +245,7 @@ Format options:
                            Defaults to false.
   --jsx-single-quote       Use single quotes in JSX.
                            Defaults to false.
-  --parser <flow|babel|babel-flow|babel-ts|typescript|css|less|scss|json|json5|json-stringify|graphql|markdown|mdx|vue|yaml|html|angular|lwc>
+  --parser <flow|babel|babel-flow|babel-ts|typescript|espree|css|less|scss|json|json5|json-stringify|graphql|markdown|mdx|vue|yaml|html|angular|lwc>
                            Which parser to use.
   --print-width <int>      The line length where Prettier will try wrap.
                            Defaults to 80.

tests_integration/__tests__/__snapshots__/help-options.js.snap

@@ -361,7 +361,7 @@ exports[`show detailed usage with --help no-semi (write) 1`] = `Array []`;
 exports[`show detailed usage with --help parser (stderr) 1`] = `""`;
 
 exports[`show detailed usage with --help parser (stdout) 1`] = `
-"--parser <flow|babel|babel-flow|babel-ts|typescript|css|less|scss|json|json5|json-stringify|graphql|markdown|mdx|vue|yaml|html|angular|lwc>
+"--parser <flow|babel|babel-flow|babel-ts|typescript|espree|css|less|scss|json|json5|json-stringify|graphql|markdown|mdx|vue|yaml|html|angular|lwc>
 
   Which parser to use.
 
@@ -372,6 +372,7 @@ Valid options:
   babel-flow       Flow
   babel-ts         TypeScript
   typescript       TypeScript
+  espree           JavaScript
   css              CSS
   less             Less
   scss             SCSS

tests_integration/__tests__/__snapshots__/plugin-options-string.js.snap

@@ -20,8 +20,8 @@ exports[` 1`] = `
                              Defaults to false.
     --jsx-single-quote       Use single quotes in JSX.
                              Defaults to false.
--   --parser <flow|babel|babel-flow|babel-ts|typescript|css|less|scss|json|json5|json-stringify|graphql|markdown|mdx|vue|yaml|html|angular|lwc>
-+   --parser <flow|babel|babel-flow|babel-ts|typescript|css|less|scss|json|json5|json-stringify|graphql|markdown|mdx|vue|yaml|html|angular|lwc|foo-parser>
+-   --parser <flow|babel|babel-flow|babel-ts|typescript|espree|css|less|scss|json|json5|json-stringify|graphql|markdown|mdx|vue|yaml|html|angular|lwc>
++   --parser <flow|babel|babel-flow|babel-ts|typescript|espree|css|less|scss|json|json5|json-stringify|graphql|markdown|mdx|vue|yaml|html|angular|lwc|foo-parser>
                              Which parser to use.
     --print-width <int>      The line length where Prettier will try wrap.
                              Defaults to 80.

tests_integration/__tests__/__snapshots__/plugin-options.js.snap

@@ -20,8 +20,8 @@ exports[` 1`] = `
                              Defaults to false.
     --jsx-single-quote       Use single quotes in JSX.
                              Defaults to false.
--   --parser <flow|babel|babel-flow|babel-ts|typescript|css|less|scss|json|json5|json-stringify|graphql|markdown|mdx|vue|yaml|html|angular|lwc>
-+   --parser <flow|babel|babel-flow|babel-ts|typescript|css|less|scss|json|json5|json-stringify|graphql|markdown|mdx|vue|yaml|html|angular|lwc|foo-parser>
+-   --parser <flow|babel|babel-flow|babel-ts|typescript|espree|css|less|scss|json|json5|json-stringify|graphql|markdown|mdx|vue|yaml|html|angular|lwc>
++   --parser <flow|babel|babel-flow|babel-ts|typescript|espree|css|less|scss|json|json5|json-stringify|graphql|markdown|mdx|vue|yaml|html|angular|lwc|foo-parser>
                              Which parser to use.
     --print-width <int>      The line length where Prettier will try wrap.
                              Defaults to 80.
@@ -32,7 +32,7 @@ exports[` 1`] = `
 exports[`include plugin's parsers to the values of the \`parser\` option\` (stderr) 1`] = `""`;
 
 exports[`include plugin's parsers to the values of the \`parser\` option\` (stdout) 1`] = `
-"--parser <flow|babel|babel-flow|babel-ts|typescript|css|less|scss|json|json5|json-stringify|graphql|markdown|mdx|vue|yaml|html|angular|lwc|foo-parser>
+"--parser <flow|babel|babel-flow|babel-ts|typescript|espree|css|less|scss|json|json5|json-stringify|graphql|markdown|mdx|vue|yaml|html|angular|lwc|foo-parser>
 
   Which parser to use.
 
@@ -43,6 +43,7 @@ Valid options:
   babel-flow       Flow
   babel-ts         TypeScript
   typescript       TypeScript
+  espree           JavaScript
   css              CSS
   less             Less
   scss             SCSS

tests_integration/__tests__/__snapshots__/schema.js.snap

@@ -162,6 +162,12 @@ This option cannot be used with --range-start and --range-end.",
                 "typescript",
               ],
             },
+            Object {
+              "description": "JavaScript",
+              "enum": Array [
+                "espree",
+              ],
+            },
             Object {
               "description": "CSS",
               "enum": Array [

tests_integration/__tests__/__snapshots__/support-info.js.snap

@@ -37,9 +37,11 @@ Object {
       "babel-ts",
       "flow",
       "typescript",
+      "espree",
     ],
     "JavaScript": Array [
       "babel",
+      "espree",
       "babel-flow",
       "babel-ts",
       "flow",
@@ -150,6 +152,7 @@ Object {
         "babel-flow",
         "babel-ts",
         "typescript",
+        "espree",
         "css",
         "less",
         "scss",
@@ -313,7 +316,14 @@ exports[`CLI --support-info (stdout) 1`] = `
       ],
       \\"linguistLanguageId\\": 183,
       \\"name\\": \\"JavaScript\\",
-      \\"parsers\\": [\\"babel\\", \\"babel-flow\\", \\"babel-ts\\", \\"flow\\", \\"typescript\\"],
+      \\"parsers\\": [
+        \\"babel\\",
+        \\"espree\\",
+        \\"babel-flow\\",
+        \\"babel-ts\\",
+        \\"flow\\",
+        \\"typescript\\"
+      ],
       \\"since\\": \\"0.0.0\\",
       \\"tmScope\\": \\"source.js\\",
       \\"type\\": \\"programming\\",
@@ -355,7 +365,14 @@ exports[`CLI --support-info (stdout) 1`] = `
       \\"group\\": \\"JavaScript\\",
       \\"linguistLanguageId\\": 178,
       \\"name\\": \\"JSX\\",
-      \\"parsers\\": [\\"babel\\", \\"babel-flow\\", \\"babel-ts\\", \\"flow\\", \\"typescript\\"],
+      \\"parsers\\": [
+        \\"babel\\",
+        \\"babel-flow\\",
+        \\"babel-ts\\",
+        \\"flow\\",
+        \\"typescript\\",
+        \\"espree\\"
+      ],
       \\"since\\": \\"0.0.0\\",
       \\"tmScope\\": \\"source.js.jsx\\",
       \\"type\\": \\"programming\\",
@@ -864,6 +881,7 @@ exports[`CLI --support-info (stdout) 1`] = `
           \\"since\\": \\"1.4.0\\",
           \\"value\\": \\"typescript\\"
         },
+        { \\"description\\": \\"JavaScript\\", \\"since\\": \\"2.2.0\\", \\"value\\": \\"espree\\" },
         { \\"description\\": \\"CSS\\", \\"since\\": \\"1.7.1\\", \\"value\\": \\"css\\" },
         { \\"description\\": \\"Less\\", \\"since\\": \\"1.7.1\\", \\"value\\": \\"less\\" },
         { \\"description\\": \\"SCSS\\", \\"since\\": \\"1.7.1\\", \\"value\\": \\"scss\\" },

website/playground/codeSamples.js

@@ -1,6 +1,7 @@
 export default function (parser) {
   switch (parser) {
     case "babel":
+    case "espree":
       return [
         'function HelloWorld({greeting = "hello", greeted = \'"World"\', silent = false, onMouseOver,}) {',
         "",

website/playground/markdown.js

@@ -38,6 +38,7 @@ function getMarkdownSyntax(options) {
     case "babel":
     case "babel-flow":
     case "flow":
+    case "espree":
       return "jsx";
     case "babel-ts":
     case "typescript":

website/playground/util.js

@@ -68,6 +68,7 @@ export function getAstAutoFold(parser) {
     case "babel-flow":
     case "babel-ts":
     case "typescript":
+    case "espree":
     case "json":
     case "json5":
     case "json-stringify":

yarn.lock

@@ -1703,9 +1703,9 @@ acorn-globals@^6.0.0:
     acorn-walk "^7.1.1"
 
 acorn-jsx@^5.2.0:
-  version "5.2.0"
-  resolved "https://registry.yarnpkg.com/acorn-jsx/-/acorn-jsx-5.2.0.tgz#4c66069173d6fdd68ed85239fc256226182b2ebe"
-  integrity sha512-HiUX/+K2YpkpJ+SzBffkM/AQ2YE03S0U1kjTLVpoJdhZMOWy8qvXVN9JdLqv2QsaQ6MPYQIuNmwD8zOiYUofLQ==
+  version "5.3.1"
+  resolved "https://registry.yarnpkg.com/acorn-jsx/-/acorn-jsx-5.3.1.tgz#fc8661e11b7ac1539c47dbfea2e72b3af34d267b"
+  integrity sha512-K0Ptm/47OKfQRpNQ2J/oIN/3QYiK6FwW+eJbILhsdxh2WTLdl+30o8aGdTbm5JbffpFFAg/g+zi1E+jvJha5ng==
 
 acorn-walk@^7.1.1:
   version "7.2.0"
@@ -3625,7 +3625,7 @@ eslint@7.11.0:
     text-table "^0.2.0"
     v8-compile-cache "^2.0.3"
 
-espree@^7.3.0:
+espree@7.3.0, espree@^7.3.0:
   version "7.3.0"
   resolved "https://registry.yarnpkg.com/espree/-/espree-7.3.0.tgz#dc30437cf67947cf576121ebd780f15eeac72348"
   integrity sha512-dksIWsvKCixn1yrEXO8UosNSxaDoSYpq9reEjZSbHLpT5hpaCAKTLBwq0RHtLrIr+c0ByiYzWT8KTMRzoRCNlw==