💥 update node/no-unsupported-features/es-syntax to recognize bigint and import()

Author: mysticatea

docs/rules/no-unsupported-features/es-syntax.md

@@ -12,11 +12,11 @@ Editor integrations of ESLint would be useful to know it in real-time.
 
 ### Supported ECMAScript features
 
-This rule supports ECMAScript 2019.
+This rule supports ECMAScript 2019 and proposals that have been approved as Stage 4 by August 2019.
 See also [TC39 finished proposals](https://github.com/tc39/proposals/blob/master/finished-proposals.md).
 
 Please configure your `.eslintrc` file to succeed to succeed in parsing the syntax.
-For example, set `2019` to `parserOptions.ecmaVersion`.
+For example, set `2020` to `parserOptions.ecmaVersion`.
 
 ### Configured Node.js version range
 
@@ -64,6 +64,11 @@ The `"ignores"` option accepts an array of the following strings.
 
 <details>
 
+**ES2020:**
+
+- `"bigint"`
+- `"dynamicImport"`
+
 **ES2019:**
 
 - `"jsonSuperset"`

lib/rules/no-unsupported-features/es-syntax.js

@@ -349,6 +349,29 @@ const features = {
             },
         ],
     },
+
+    //--------------------------------------------------------------------------
+    // ES2020
+    //--------------------------------------------------------------------------
+    bigint: {
+        ruleId: "no-bigint",
+        cases: [
+            {
+                supported: "10.4.0",
+                test: info => info.node.type === "Literal",
+                messageId: "no-bigint",
+            },
+        ],
+    },
+    dynamicImport: {
+        ruleId: "no-dynamic-import",
+        cases: [
+            {
+                supported: null,
+                messageId: "no-dynamic-import",
+            },
+        ],
+    },
 }
 const keywords = Object.keys(features)
 
@@ -620,6 +643,14 @@ module.exports = {
                 "'\\u{{code}}' in string literals is not supported until Node.js {{supported}}. The configured version range is '{{version}}'.",
             "no-optional-catch-binding":
                 "The omission of 'catch' binding is not supported until Node.js {{supported}}. The configured version range is '{{version}}'.",
+
+            //------------------------------------------------------------------
+            // ES2020
+            //------------------------------------------------------------------
+            "no-bigint":
+                "Bigint literals are not supported until Node.js {{supported}}. The configured version range is '{{version}}'.",
+            "no-dynamic-import":
+                "'import()' expressions are not supported until Node.js {{supported}}. The configured version range is '{{version}}'.",
         },
     },
     create(context) {

package.json

@@ -13,7 +13,7 @@
     "eslint": ">=5.16.0"
   },
   "dependencies": {
-    "eslint-plugin-es": "^1.4.1",
+    "eslint-plugin-es": "^2.0.0",
     "eslint-utils": "^1.4.2",
     "ignore": "^5.1.1",
     "minimatch": "^3.0.4",
@@ -23,7 +23,7 @@
   "devDependencies": {
     "@mysticatea/eslint-plugin": "^10.0.3",
     "codecov": "^3.3.0",
-    "eslint": "^5.16.0",
+    "eslint": "^6.3.0",
     "eslint-plugin-node": "file:.",
     "fast-glob": "^2.2.6",
     "globals": "^11.12.0",

tests/lib/rules/no-unsupported-features/es-syntax.js

@@ -5,10 +5,17 @@
 "use strict"
 
 const path = require("path")
-const { RuleTester } = require("eslint")
-const globals = require("globals")
+const { Linter, RuleTester } = require("eslint")
+const { builtin } = require("globals")
 const rule = require("../../../../lib/rules/no-unsupported-features/es-syntax")
 
+const ES2020Supported = (() => {
+    const config = { parserOptions: { ecmaVersion: 2020 } }
+    const messages = new Linter().verify("0n", config)
+    return messages.length === 0
+})()
+const ecmaVersion = ES2020Supported ? 2020 : 2019
+
 /**
  * Makes a file path to a fixture.
  * @param {string} name - A name.
@@ -57,7 +64,11 @@ function concat(patterns) {
         invalid: [],
     }
 
-    for (const { keyword, valid, invalid } of patterns) {
+    for (const { requiredEcmaVersion, keyword, valid, invalid } of patterns) {
+        if (requiredEcmaVersion && ecmaVersion < requiredEcmaVersion) {
+            continue
+        }
+
         ret.valid.push(...valid)
         ret.invalid.push(...invalid)
 
@@ -71,8 +82,8 @@ function concat(patterns) {
 }
 
 const ruleTester = new RuleTester({
-    parserOptions: { ecmaVersion: 2019 },
-    globals: globals.es2017,
+    parserOptions: { ecmaVersion },
+    globals: builtin,
 })
 ruleTester.run(
     "no-unsupported-features/es-syntax",
@@ -2376,6 +2387,72 @@ ruleTester.run(
             ],
         },
 
+        //----------------------------------------------------------------------
+        // ES2020
+        //----------------------------------------------------------------------
+        {
+            keyword: "bigint",
+            requiredEcmaVersion: 2020,
+            valid: [
+                {
+                    code: "var n = 0n",
+                    options: [{ version: "10.4.0" }],
+                },
+                {
+                    code: "var n = BigInt(0)",
+                    options: [{ version: "10.3.0" }],
+                },
+                {
+                    code: "var n = new BigInt64Array()",
+                    options: [{ version: "10.3.0" }],
+                },
+                {
+                    code: "var n = new BigUint64Array()",
+                    options: [{ version: "10.3.0" }],
+                },
+            ],
+            invalid: [
+                {
+                    code: "var n = 0n",
+                    options: [{ version: "10.3.0" }],
+                    errors: [
+                        {
+                            messageId: "no-bigint",
+                            data: {
+                                supported: "10.4.0",
+                                version: "10.3.0",
+                            },
+                        },
+                    ],
+                },
+            ],
+        },
+        {
+            keyword: "dynamicImport",
+            requiredEcmaVersion: 2020,
+            valid: [
+                {
+                    code: "obj.import(source)",
+                    options: [{ version: "12.0.0" }],
+                },
+            ],
+            invalid: [
+                {
+                    code: "import(source)",
+                    options: [{ version: "12.0.0" }],
+                    errors: [
+                        {
+                            messageId: "no-dynamic-import",
+                            data: {
+                                supported: null,
+                                version: "12.0.0",
+                            },
+                        },
+                    ],
+                },
+            ],
+        },
+
         //----------------------------------------------------------------------
         // MISC
         //----------------------------------------------------------------------