Support TypeScript 4.1 via typescript-estree (#9636)

* Update typescript and typescript-estree

* Add AST transformation for TSTemplateLiteralType

* Update tests for template-literal-types

* Fix transformChainExpression

* Update tests for key-remapping-in-mapped-types

* Implement recoverInvalidDecorators

* Update changelog

* Avoid typecheck error

* Add os.platform() shim

* Update config.js

* Update config.js

* Shim os.cpus

* Update `process.versions.node`

* Attempt to fix build

* Update ts parserOptions

* Fix code style

* Remove `errorOnUnknownASTType`, fix code style

* Use `[] ||` instead of `[] //`

* Fix hack

* Add invalid tests

* checkMissingDecorators

* Update tests

* Fix tests

* Add comment

* Revert "Implement recoverInvalidDecorators"

This reverts commit 27e7b46ed41df36fb585791117c85e1b2dab932c.

* Add ref pr link

* Simplify logic

* Don't transform `TSTemplateLiteralType`

* Add `TSTemplateLiteralType` as simple type

* Fix tests

* Update comments

* Add comment

* Fix logic

* Minor tweak

* use multiple parsers

* Update @typescript-eslint/typescript-estree to v4.8.0

* Switch to `parseWithNodeMaps`

* Rename `esNode` -> `esTreeNode`

* Update @typescript-eslint/typescript-estree to 4.8.1-alpha.1

* Use @typescript-eslint/typescript-estree 4.8.1

Co-authored-by: fisker Cheung <lionkay@gmail.com>

changelog_unreleased/typescript/pr-9473.md

@@ -1,6 +1,4 @@
-#### [HIGHLIGHT]Support TypeScript 4.1 via Babel (#9473 by @sosukesuzuki)
-
-`--parser=babel-ts` is required.
+#### [HIGHLIGHT]Support TypeScript 4.1 (#9473, #9636 by @sosukesuzuki)
 
 ##### Key Remapping In Mapped Types
 

package.json

@@ -25,7 +25,7 @@
     "@babel/parser": "7.12.5",
     "@glimmer/syntax": "0.66.0",
     "@iarna/toml": "2.2.5",
-    "@typescript-eslint/typescript-estree": "3.10.1",
+    "@typescript-eslint/typescript-estree": "4.8.1",
     "angular-estree-parser": "2.2.1",
     "angular-html-parser": "1.7.1",
     "camelcase": "6.2.0",
@@ -78,7 +78,7 @@
     "resolve": "1.19.0",
     "semver": "7.3.2",
     "string-width": "4.2.0",
-    "typescript": "4.0.5",
+    "typescript": "4.1.1-rc",
     "unicode-regex": "3.0.0",
     "unified": "9.2.0",
     "vnopts": "1.0.2",

scripts/build/config.js

@@ -40,6 +40,11 @@ const parsers = [
       // `TypeScript`, `toolsVersion`, `globalThis`
       'typeof process === "undefined" || process.browser': "false",
       'typeof globalThis === "object"': "true",
+      // `@typescript-eslint/typescript-estree` v4
+      'require("globby")': "{}",
+      "extra.projects = prepareAndTransformProjects(":
+        "extra.projects = [] || prepareAndTransformProjects(",
+      "process.versions.node": "'999.999.999'",
     },
   },
   {

scripts/build/shims/os.mjs

@@ -1,3 +1,5 @@
 export default {
   EOL: "\n",
+  platform: () => "browser",
+  cpus: () => [{ model: "Prettier" }],
 };

src/language-graphql/printer-graphql.js

@@ -1,15 +1,8 @@
 "use strict";
 
 const {
-  concat,
-  join,
-  hardline,
-  line,
-  softline,
-  group,
-  indent,
-  ifBreak,
-} = require("../document").builders;
+  builders: { concat, join, hardline, line, softline, group, indent, ifBreak },
+} = require("../document");
 const { isNextLineEmpty } = require("../common/util");
 const { insertPragma } = require("./pragma");
 const { locStart, locEnd } = require("./loc");

src/language-handlebars/printer-glimmer.js

@@ -1,15 +1,8 @@
 "use strict";
 
 const {
-  concat,
-  group,
-  hardline,
-  ifBreak,
-  indent,
-  join,
-  line,
-  softline,
-} = require("../document").builders;
+  builders: { concat, group, hardline, ifBreak, indent, join, line, softline },
+} = require("../document");
 const { locStart, locEnd } = require("./loc");
 const clean = require("./clean");
 const {

src/language-js/parse-postprocess.js

@@ -5,6 +5,7 @@ const {
   getNextNonSpaceNonCommentCharacter,
   getShebang,
 } = require("../common/util");
+const createError = require("../common/parser-create-error");
 const { composeLoc, locStart, locEnd } = require("./loc");
 const { isTypeCastComment } = require("./comments");
 
@@ -17,6 +18,50 @@ function postprocess(ast, options) {
     includeShebang(ast, options);
   }
 
+  // Invalid decorators are removed since `@typescript-eslint/typescript-estree` v4
+  // https://github.com/typescript-eslint/typescript-eslint/pull/2375
+  if (options.parser === "typescript" && options.originalText.includes("@")) {
+    const {
+      esTreeNodeToTSNodeMap,
+      tsNodeToESTreeNodeMap,
+    } = options.tsParseResult;
+    ast = visitNode(ast, (node) => {
+      const tsNode = esTreeNodeToTSNodeMap.get(node);
+      if (!tsNode) {
+        return;
+      }
+      const tsDecorators = tsNode.decorators;
+      if (!Array.isArray(tsDecorators)) {
+        return;
+      }
+      // `esTreeNodeToTSNodeMap.get(ClassBody)` and `esTreeNodeToTSNodeMap.get(ClassDeclaration)` has the same tsNode
+      const esTreeNode = tsNodeToESTreeNodeMap.get(tsNode);
+      if (esTreeNode !== node) {
+        return;
+      }
+      const esTreeDecorators = esTreeNode.decorators;
+      if (
+        !Array.isArray(esTreeDecorators) ||
+        esTreeDecorators.length !== tsDecorators.length ||
+        tsDecorators.some((tsDecorator) => {
+          const esTreeDecorator = tsNodeToESTreeNodeMap.get(tsDecorator);
+          return (
+            !esTreeDecorator || !esTreeDecorators.includes(esTreeDecorator)
+          );
+        })
+      ) {
+        const { start, end } = esTreeNode.loc;
+        throw createError(
+          "Leading decorators must be attached to a class declaration",
+          {
+            start: { line: start.line, column: start.column + 1 },
+            end: { line: end.line, column: end.column + 1 },
+          }
+        );
+      }
+    });
+  }
+
   // Keep Babel's non-standard ParenthesizedExpression nodes only if they have Closure-style type cast comments.
   if (
     options.parser !== "typescript" &&
@@ -146,9 +191,9 @@ 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`
+// This is a workaround to transform `ChainExpression` from `espree`, `meriyah`,
+// and `typescript` 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") {
@@ -158,6 +203,10 @@ function transformChainExpression(node) {
     node.type = "OptionalMemberExpression";
     node.object = transformChainExpression(node.object);
   }
+  // typescript
+  else if (node.type === "TSNonNullExpression") {
+    node.expression = transformChainExpression(node.expression);
+  }
   return node;
 }
 
@@ -180,6 +229,10 @@ function visitNode(node, fn) {
     node[key] = visitNode(child, fn);
   }
 
+  if (Array.isArray(node)) {
+    return node;
+  }
+
   return fn(node) || node;
 }
 

src/language-js/parser-typescript.js

@@ -7,14 +7,14 @@ const postprocess = require("./parse-postprocess");
 
 function parse(text, parsers, opts) {
   const jsx = isProbablyJsx(text);
-  let ast;
+  let result;
   try {
     // Try passing with our best guess first.
-    ast = tryParseTypeScript(text, jsx);
+    result = tryParseTypeScript(text, jsx);
   } catch (firstError) {
     try {
       // But if we get it wrong, try the opposite.
-      ast = tryParseTypeScript(text, !jsx);
+      result = tryParseTypeScript(text, !jsx);
     } catch (secondError) {
       // Suppose our guess is correct, throw the first error
       const { message, lineNumber, column } = firstError;
@@ -30,12 +30,16 @@ function parse(text, parsers, opts) {
     }
   }
 
-  return postprocess(ast, { ...opts, originalText: text });
+  return postprocess(result.ast, {
+    ...opts,
+    originalText: text,
+    tsParseResult: result,
+  });
 }
 
 function tryParseTypeScript(text, jsx) {
-  const parser = require("@typescript-eslint/typescript-estree");
-  return parser.parse(text, {
+  const { parseWithNodeMaps } = require("@typescript-eslint/typescript-estree");
+  return parseWithNodeMaps(text, {
     // `jest@<=26.4.2` rely on `loc`
     // https://github.com/facebook/jest/issues/10444
     loc: true,
@@ -45,6 +49,7 @@ function tryParseTypeScript(text, jsx) {
     jsx,
     tokens: true,
     loggerFn: false,
+    project: [],
   });
 }
 

src/language-js/print/template-literal.js

@@ -24,17 +24,24 @@ const {
 
 function printTemplateLiteral(path, print, options) {
   const node = path.getValue();
-  const parentNode = path.getParentNode();
+  const isTemplateLiteral = node.type === "TemplateLiteral";
 
-  if (isJestEachTemplateLiteral(node, parentNode)) {
+  if (
+    isTemplateLiteral &&
+    isJestEachTemplateLiteral(node, path.getParentNode())
+  ) {
     const printed = printJestEachTemplateLiteral(path, options, print);
     if (printed) {
       return printed;
     }
   }
+  let expressionsKey = "expressions";
+  if (node.type === "TSTemplateLiteralType") {
+    expressionsKey = "types";
+  }
   const parts = [];
 
-  let expressions = path.map(print, "expressions");
+  let expressions = path.map(print, expressionsKey);
   const isSimple = isSimpleTemplateLiteral(node);
 
   if (isSimple) {
@@ -70,7 +77,7 @@ function printTemplateLiteral(path, print, options) {
       let printed = expressions[i];
 
       if (!isSimple) {
-        const expression = node.expressions[i];
+        const expression = node[expressionsKey][i];
         // Breaks at the template element boundaries (${ and }) are preferred to breaking
         // in the middle of a MemberExpression
         if (

src/language-js/printer-estree-json.js

@@ -1,6 +1,8 @@
 "use strict";
 
-const { concat, hardline, indent, join } = require("../document").builders;
+const {
+  builders: { concat, hardline, indent, join },
+} = require("../document");
 const preprocess = require("./print-preprocess");
 
 function genericPrint(path, options, print) {

src/language-js/printer-estree.js

@@ -2238,6 +2238,7 @@ function printPathNoParens(path, options, print, args) {
       return concat(parts);
     case "TemplateElement":
       return join(literalline, n.value.raw.split(/\r?\n/g));
+    case "TSTemplateLiteralType":
     case "TemplateLiteral": {
       return printTemplateLiteral(path, print, options);
     }

src/language-js/utils.js

@@ -464,6 +464,7 @@ const simpleTypeAnnotations = new Set([
   "BigIntLiteralTypeAnnotation",
   "NumberLiteralTypeAnnotation",
   "TSLiteralType",
+  "TSTemplateLiteralType",
   // flow only, `empty`, `mixed`
   "EmptyTypeAnnotation",
   "MixedTypeAnnotation",
@@ -647,11 +648,17 @@ function isNgForOf(node, index, parentNode) {
  * @returns {boolean}
  */
 function isSimpleTemplateLiteral(node) {
-  if (node.expressions.length === 0) {
+  let expressionsKey = "expressions";
+  if (node.type === "TSTemplateLiteralType") {
+    expressionsKey = "types";
+  }
+  const expressions = node[expressionsKey];
+
+  if (expressions.length === 0) {
     return false;
   }
 
-  return node.expressions.every((expr) => {
+  return expressions.every((expr) => {
     // Disallow comments since printDocToString can't print them here
     if (expr.comments) {
       return false;

src/main/comments.js

@@ -4,15 +4,17 @@
 const assert = require("assert");
 
 const {
-  concat,
-  line,
-  hardline,
-  breakParent,
-  indent,
-  lineSuffix,
-  join,
-  cursor,
-} = require("../document").builders;
+  builders: {
+    concat,
+    line,
+    hardline,
+    breakParent,
+    indent,
+    lineSuffix,
+    join,
+    cursor,
+  },
+} = require("../document");
 
 const {
   hasNewline,

tests/misc/errors/invalid-typescript-decorators/__snapshots__/jsfmt.spec.js.snap

@@ -0,0 +1,96 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`decorator.ts [babel-ts] format 1`] = `
+"Leading decorators must be attached to a class declaration (4:1)
+  2 | 
+  3 | @dec
+> 4 | enum E {}
+    | ^
+  5 | "
+`;
+
+exports[`decorator.ts [typescript] format 1`] = `
+"Leading decorators must be attached to a class declaration (3:1)
+  1 | declare function dec<T>(target: T): T;
+  2 | 
+> 3 | @dec
+    | ^^^^
+> 4 | enum E {}
+    | ^^^^^^^^^^
+  5 | "
+`;
+
+exports[`enums.ts [babel-ts] format 1`] = `
+"Leading decorators must be attached to a class declaration (4:1)
+  2 | 
+  3 | @decorator()
+> 4 | enum Direction {
+    | ^
+  5 |                Up = 1,
+  6 |   Down,
+  7 |   Left,"
+`;
+
+exports[`enums.ts [typescript] format 1`] = `
+"Leading decorators must be attached to a class declaration (3:1)
+   1 | // https://github.com/typescript-eslint/typescript-eslint/pull/2375
+   2 | 
+>  3 | @decorator()
+     | ^^^^^^^^^^^^
+>  4 | enum Direction {
+     | ^^^^^^^^^^^^^^^^
+>  5 |                Up = 1,
+     | ^^^^^^^^^^^^^^^^
+>  6 |   Down,
+     | ^^^^^^^^^^^^^^^^
+>  7 |   Left,
+     | ^^^^^^^^^^^^^^^^
+>  8 |   Right
+     | ^^^^^^^^^^^^^^^^
+>  9 | }
+     | ^^
+  10 | "
+`;
+
+exports[`function.ts [babel-ts] format 1`] = `
+"Leading decorators must be attached to a class declaration (4:1)
+  2 | 
+  3 | @decorator()
+> 4 | function foo(      ){}
+    | ^
+  5 | "
+`;
+
+exports[`function.ts [typescript] format 1`] = `
+"Leading decorators must be attached to a class declaration (3:1)
+  1 | // https://github.com/typescript-eslint/typescript-eslint/pull/2375
+  2 | 
+> 3 | @decorator()
+    | ^^^^^^^^^^^^
+> 4 | function foo(      ){}
+    | ^^^^^^^^^^^^^^^^^^^^^^^
+  5 | "
+`;
+
+exports[`interface.ts [babel-ts] format 1`] = `
+"Leading decorators must be attached to a class declaration (5:1)
+  3 | 
+  4 | @hello()
+> 5 | interface MyInterface {id: string;
+    | ^
+  6 | }
+  7 | "
+`;
+
+exports[`interface.ts [typescript] format 1`] = `
+"Leading decorators must be attached to a class declaration (4:1)
+  2 | // #4632
+  3 | 
+> 4 | @hello()
+    | ^^^^^^^^
+> 5 | interface MyInterface {id: string;
+    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+> 6 | }
+    | ^^
+  7 | "
+`;

tests/misc/errors/invalid-typescript-decorators/enums.ts

@@ -0,0 +1,9 @@
+// https://github.com/typescript-eslint/typescript-eslint/pull/2375
+
+@decorator()
+enum Direction {
+               Up = 1,
+  Down,
+  Left,
+  Right
+}

tests/misc/errors/invalid-typescript-decorators/function.ts

@@ -0,0 +1,4 @@
+// https://github.com/typescript-eslint/typescript-eslint/pull/2375
+
+@decorator()
+function foo(      ){}

tests/misc/errors/invalid-typescript-decorators/interface.ts

@@ -1,6 +1,6 @@
 // invalid place but shouldn't be removed
+// #4632
 
 @hello()
-interface MyInterface {
-  id: string;
+interface MyInterface {id: string;
 }

tests/misc/errors/invalid-typescript-decorators/jsfmt.spec.js

@@ -0,0 +1 @@
+run_spec(__dirname, ["typescript", "babel-ts"]);

tests/typescript/conformance/types/decorator/__snapshots__/jsfmt.spec.js.snap

@@ -1,30 +0,0 @@
-// Jest Snapshot v1, https://goo.gl/fbAQLP
-
-exports[`decorator.ts [babel-ts] format 1`] = `
-"Leading decorators must be attached to a class declaration (4:1)
-  2 | 
-  3 | @dec
-> 4 | enum E {}
-    | ^
-  5 | "
-`;
-
-exports[`decorator.ts format 1`] = `
-====================================options=====================================
-parsers: ["typescript"]
-printWidth: 80
-                                                                                | printWidth
-=====================================input======================================
-declare function dec<T>(target: T): T;
-
-@dec
-enum E {}
-
-=====================================output=====================================
-declare function dec<T>(target: T): T;
-
-@dec
-enum E {}
-
-================================================================================
-`;

tests/typescript/conformance/types/decorator/jsfmt.spec.js

@@ -1 +0,0 @@
-run_spec(__dirname, ["typescript"], { errors: { "babel-ts": true } });

tests/typescript/decorators/__snapshots__/jsfmt.spec.js.snap

@@ -395,38 +395,3 @@ class MyContainerComponent {
 
 ================================================================================
 `;
-
-exports[`interface.ts [babel-ts] format 1`] = `
-"Leading decorators must be attached to a class declaration (4:1)
-  2 | 
-  3 | @hello()
-> 4 | interface MyInterface {
-    | ^
-  5 |   id: string;
-  6 | }
-  7 | "
-`;
-
-exports[`interface.ts format 1`] = `
-====================================options=====================================
-parsers: ["typescript"]
-printWidth: 80
-                                                                                | printWidth
-=====================================input======================================
-// invalid place but shouldn't be removed
-
-@hello()
-interface MyInterface {
-  id: string;
-}
-
-=====================================output=====================================
-// invalid place but shouldn't be removed
-
-@hello()
-interface MyInterface {
-  id: string;
-}
-
-================================================================================
-`;

tests/typescript/decorators/jsfmt.spec.js

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

tests/typescript/key-remapping-in-mapped-types/__snapshots__/jsfmt.spec.js.snap

@@ -1,15 +1,5 @@
 // Jest Snapshot v1, https://goo.gl/fbAQLP
 
-exports[`key-remapping.ts [typescript] format 1`] = `
-"']' expected. (2:17)
-  1 | type MappedTypeWithNewKeys<T> = {
-> 2 |   [K in keyof T as NewKeyType]: T[K]
-    |                 ^
-  3 | };
-  4 |   
-  5 | type RemoveKindField<T> = {"
-`;
-
 exports[`key-remapping.ts format 1`] = `
 ====================================options=====================================
 parsers: ["babel-ts", "typescript"]

tests/typescript/key-remapping-in-mapped-types/jsfmt.spec.js

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

tests/typescript/template-literal-types/__snapshots__/jsfmt.spec.js.snap

@@ -1,14 +1,5 @@
 // Jest Snapshot v1, https://goo.gl/fbAQLP
 
-exports[`template-literal-types.ts [typescript] format 1`] = `
-"Type expected. (1:8)
-> 1 | let x: \`foo-\${infer bar}\`;
-    |        ^
-  2 | type HelloWorld = \`\${Hello}, \${World}\`
-  3 | type SeussFish = \`\${Quantity | Color} fish\`;
-  4 | declare function setAlignment(value: \`\${VerticalAlignment}-\${HorizontalAlignment}\`): void;"
-`;
-
 exports[`template-literal-types.ts format 1`] = `
 ====================================options=====================================
 parsers: ["babel-ts", "typescript"]

tests/typescript/template-literal-types/jsfmt.spec.js

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

tests/typescript/typeparams/consistent/__snapshots__/jsfmt.spec.js.snap

@@ -71,6 +71,41 @@ const foo12: Foooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooo
 ================================================================================
 `;
 
+exports[`template-literal-types.ts [babel] format 1`] = `
+"Unexpected token (1:84)
+> 1 | const foo1: Fooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooo<\`Hello, \${keyof World}\`> = a;
+    |                                                                                    ^
+  2 | "
+`;
+
+exports[`template-literal-types.ts [babel-flow] format 1`] = `
+"Unexpected token (1:84)
+> 1 | const foo1: Fooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooo<\`Hello, \${keyof World}\`> = a;
+    |                                                                                    ^
+  2 | "
+`;
+
+exports[`template-literal-types.ts [flow] format 1`] = `
+"Unexpected token \`\`\` (1:84)
+> 1 | const foo1: Fooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooo<\`Hello, \${keyof World}\`> = a;
+    |                                                                                    ^
+  2 | "
+`;
+
+exports[`template-literal-types.ts format 1`] = `
+====================================options=====================================
+parsers: ["typescript", "flow", "babel-flow", "babel"]
+printWidth: 80
+                                                                                | printWidth
+=====================================input======================================
+const foo1: Fooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooo<\`Hello, \${keyof World}\`> = a;
+
+=====================================output=====================================
+const foo1: Fooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooo<\`Hello, \${keyof World}\`> = a;
+
+================================================================================
+`;
+
 exports[`typescript-only.ts format 1`] = `
 ====================================options=====================================
 parsers: ["typescript", "flow", "babel-flow", "babel"]
@@ -81,6 +116,7 @@ const foo1: Fooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooo
 const foo2: Fooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooo<object> = a;
 const foo3: Fooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooo<undefined> = a;
 const foo4: Fooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooo<unknown> = a;
+
 =====================================output=====================================
 const foo1: Fooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooo<never> = a;
 const foo2: Fooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooo<object> = a;

tests/typescript/typeparams/consistent/jsfmt.spec.js

@@ -1 +1,7 @@
-run_spec(__dirname, ["typescript", "flow", "babel-flow", "babel"]);
+run_spec(__dirname, ["typescript", "flow", "babel-flow", "babel"], {
+  errors: {
+    flow: ["template-literal-types.ts"],
+    "babel-flow": ["template-literal-types.ts"],
+    babel: ["template-literal-types.ts"],
+  },
+});

tests/typescript/typeparams/consistent/template-literal-types.ts

@@ -0,0 +1 @@
+const foo1: Fooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooo<`Hello, ${keyof World}`> = a;

tests/typescript/typeparams/consistent/typescript-only.ts

@@ -1,4 +1,4 @@
 const foo1: Fooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooo<never> = a;
 const foo2: Fooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooo<object> = a;
 const foo3: Fooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooo<undefined> = a;
-const foo4: Fooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooo<unknown> = a;
+const foo4: Fooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooo<unknown> = a;

yarn.lock

@@ -1465,19 +1465,10 @@
   resolved "https://registry.yarnpkg.com/@typescript-eslint/types/-/types-4.0.1.tgz#1cf72582f764931f085cb8230ff215980fe467b2"
   integrity sha512-S+gD3fgbkZYW2rnbjugNMqibm9HpEjqZBZkTiI3PwbbNGWmAcxolWIUwZ0SKeG4Dy2ktpKKaI/6+HGYVH8Qrlg==
 
-"@typescript-eslint/typescript-estree@3.10.1":
-  version "3.10.1"
-  resolved "https://registry.yarnpkg.com/@typescript-eslint/typescript-estree/-/typescript-estree-3.10.1.tgz#fd0061cc38add4fad45136d654408569f365b853"
-  integrity sha512-QbcXOuq6WYvnB3XPsZpIwztBoquEYLXh2MtwVU+kO8jgYCiv4G5xrSP/1wg4tkvrEE+esZVquIPX/dxPlePk1w==
-  dependencies:
-    "@typescript-eslint/types" "3.10.1"
-    "@typescript-eslint/visitor-keys" "3.10.1"
-    debug "^4.1.1"
-    glob "^7.1.6"
-    is-glob "^4.0.1"
-    lodash "^4.17.15"
-    semver "^7.3.2"
-    tsutils "^3.17.1"
+"@typescript-eslint/types@4.8.1":
+  version "4.8.1"
+  resolved "https://registry.yarnpkg.com/@typescript-eslint/types/-/types-4.8.1.tgz#23829c73c5fc6f4fcd5346a7780b274f72fee222"
+  integrity sha512-ave2a18x2Y25q5K05K/U3JQIe2Av4+TNi/2YuzyaXLAsDx6UZkz1boZ7nR/N6Wwae2PpudTZmHFXqu7faXfHmA==
 
 "@typescript-eslint/typescript-estree@4.0.1":
   version "4.0.1"
@@ -1493,12 +1484,19 @@
     semver "^7.3.2"
     tsutils "^3.17.1"
 
-"@typescript-eslint/visitor-keys@3.10.1":
-  version "3.10.1"
-  resolved "https://registry.yarnpkg.com/@typescript-eslint/visitor-keys/-/visitor-keys-3.10.1.tgz#cd4274773e3eb63b2e870ac602274487ecd1e931"
-  integrity sha512-9JgC82AaQeglebjZMgYR5wgmfUdUc+EitGUUMW8u2nDckaeimzW+VsoLV6FoimPv2id3VQzfjwBxEMVz08ameQ==
+"@typescript-eslint/typescript-estree@4.8.1":
+  version "4.8.1"
+  resolved "https://registry.yarnpkg.com/@typescript-eslint/typescript-estree/-/typescript-estree-4.8.1.tgz#7307e3f2c9e95df7daa8dc0a34b8c43b7ec0dd32"
+  integrity sha512-bJ6Fn/6tW2g7WIkCWh3QRlaSU7CdUUK52shx36/J7T5oTQzANvi6raoTsbwGM11+7eBbeem8hCCKbyvAc0X3sQ==
   dependencies:
-    eslint-visitor-keys "^1.1.0"
+    "@typescript-eslint/types" "4.8.1"
+    "@typescript-eslint/visitor-keys" "4.8.1"
+    debug "^4.1.1"
+    globby "^11.0.1"
+    is-glob "^4.0.1"
+    lodash "^4.17.15"
+    semver "^7.3.2"
+    tsutils "^3.17.1"
 
 "@typescript-eslint/visitor-keys@4.0.1":
   version "4.0.1"
@@ -1508,6 +1506,14 @@
     "@typescript-eslint/types" "4.0.1"
     eslint-visitor-keys "^2.0.0"
 
+"@typescript-eslint/visitor-keys@4.8.1":
+  version "4.8.1"
+  resolved "https://registry.yarnpkg.com/@typescript-eslint/visitor-keys/-/visitor-keys-4.8.1.tgz#794f68ee292d1b2e3aa9690ebedfcb3a8c90e3c3"
+  integrity sha512-3nrwXFdEYALQh/zW8rFwP4QltqsanCDz4CwWMPiIZmwlk9GlvBeueEIbq05SEq4ganqM0g9nh02xXgv5XI3PeQ==
+  dependencies:
+    "@typescript-eslint/types" "4.8.1"
+    eslint-visitor-keys "^2.0.0"
+
 "@webassemblyjs/ast@1.9.0":
   version "1.9.0"
   resolved "https://registry.yarnpkg.com/@webassemblyjs/ast/-/ast-1.9.0.tgz#bd850604b4042459a5a41cd7d338cbed695ed964"
@@ -7165,10 +7171,10 @@ typedarray-to-buffer@^3.1.5:
   dependencies:
     is-typedarray "^1.0.0"
 
-typescript@4.0.5:
-  version "4.0.5"
-  resolved "https://registry.yarnpkg.com/typescript/-/typescript-4.0.5.tgz#ae9dddfd1069f1cb5beb3ef3b2170dd7c1332389"
-  integrity sha512-ywmr/VrTVCmNTJ6iV2LwIrfG1P+lv6luD8sUJs+2eI9NLGigaN+nUQc13iHqisq7bra9lnmUSYqbJvegraBOPQ==
+typescript@4.1.1-rc:
+  version "4.1.1-rc"
+  resolved "https://registry.yarnpkg.com/typescript/-/typescript-4.1.1-rc.tgz#4a335244b9b2754995849ca4b607c74d6ee73719"
+  integrity sha512-tgNcFrLIjlaMWEc7bKC0bxLNIt8BIAauY/HLUOQDyTP75HGskETtXOt46x4EKAHRKhWVLMc7yM02puTHa/yhCA==
 
 unherit@^1.0.4:
   version "1.1.3"