invalidate ESM imports that were valid in Node 10

.nycrc

@@ -4,7 +4,8 @@
     ],
     "exclude": [
         "lib/rules/no-hide-core-modules.js",
-        "lib/rules/no-unsupported-features.js"
+        "lib/rules/no-unsupported-features.js",
+        "lib/converted-esm/*.js"
     ],
     "reporter": [
         "lcov",

docs/rules/file-extension-in-import.md

@@ -27,7 +27,6 @@ This rule has a string option and an object option.
         "error",
         "always" or "never",
         {
-            "tryExtensions": [".js", ".json", ".node"],
             ".xxx": "always" or "never",
         }
     ]
@@ -36,7 +35,6 @@ This rule has a string option and an object option.
 
 - `"always"` (default) requires file extensions in `import`/`export` declarations.
 - `"never"` disallows file extensions in `import`/`export` declarations.
-- `tryExtensions` is the file extensions to resolve import paths. Default is `[".js", ".json", ".node"]`.
 - `.xxx` is the overriding setting for specific file extensions. You can use arbitrary property names which start with `.`.
 
 #### always
@@ -90,27 +88,6 @@ import styles from "./styles.css"
 import logo from "./logo.png"
 ```
 
-### Shared Settings
-
-The following options can be set by [shared settings](http://eslint.org/docs/user-guide/configuring.html#adding-shared-settings).
-Several rules have the same option, but we can set this option at once.
-
-- `tryExtensions`
-
-```js
-// .eslintrc.js
-module.exports = {
-    "settings": {
-        "node": {
-            "tryExtensions": [".js", ".json", ".node"]
-        }
-    },
-    "rules": {
-        "n/file-extension-in-import": "error"
-    }
-}
-```
-
 ## 🔎 Implementation
 
 - [Rule source](../../lib/rules/file-extension-in-import.js)

docs/rules/no-extraneous-import.md

@@ -17,7 +17,6 @@ This rule warns `import` declarations of extraneous modules.
         "n/no-extraneous-import": ["error", {
             "allowModules": [],
             "resolvePaths": [],
-            "tryExtensions": []
         }]
     }
 }
@@ -48,21 +47,13 @@ If a path is relative, it will be resolved from CWD.
 
 Default is `[]`
 
-#### tryExtensions
-
-When an import path does not exist, this rule checks whether or not any of `path.js`, `path.json`, and `path.node` exists.
-`tryExtensions` option is the extension list this rule uses at the time.
-
-Default is `[".js", ".json", ".node"]`.
-
 ### Shared Settings
 
 The following options can be set by [shared settings](http://eslint.org/docs/user-guide/configuring.html#adding-shared-settings).
 Several rules have the same option, but we can set this option at once.
 
 - `allowModules`
 - `resolvePaths`
-- `tryExtensions`
 
 ```js
 // .eslintrc.js
@@ -71,7 +62,6 @@ module.exports = {
         "node": {
             "allowModules": ["electron"],
             "resolvePaths": [__dirname],
-            "tryExtensions": [".js", ".json", ".node"]
         }
     },
     "rules": {

docs/rules/no-missing-import.md

@@ -37,7 +37,6 @@ import existingModule from "existing-module";
         "n/no-missing-import": ["error", {
             "allowModules": [],
             "resolvePaths": ["/path/to/a/modules/directory"],
-            "tryExtensions": [".js", ".json", ".node"]
         }]
     }
 }
@@ -68,21 +67,13 @@ If a path is relative, it will be resolved from CWD.
 
 Default is `[]`
 
-#### tryExtensions
-
-When an import path does not exist, this rule checks whether or not any of `path.js`, `path.json`, and `path.node` exists.
-`tryExtensions` option is the extension list this rule uses at the time.
-
-Default is `[".js", ".json", ".node"]`.
-
 ### Shared Settings
 
 The following options can be set by [shared settings](http://eslint.org/docs/user-guide/configuring.html#adding-shared-settings).
 Several rules have the same option, but we can set this option at once.
 
 - `allowModules`
 - `resolvePaths`
-- `tryExtensions`
 
 ```js
 // .eslintrc.js
@@ -91,7 +82,6 @@ module.exports = {
         "node": {
             "allowModules": ["electron"],
             "resolvePaths": [__dirname],
-            "tryExtensions": [".js", ".json", ".node"]
         }
     },
     "rules": {

docs/rules/no-unpublished-import.md

@@ -26,7 +26,6 @@ Then this rule warns `import` declarations in \*published\* files if the `import
         "n/no-unpublished-import": ["error", {
             "allowModules": [],
             "convertPath": null,
-            "tryExtensions": [".js", ".json", ".node"]
         }]
     }
 }
@@ -64,7 +63,6 @@ For example:
             "convertPath": {
                 "src/**/*.jsx": ["^src/(.+?)\\.jsx$", "lib/$1.js"]
             },
-            "tryExtensions": [".js", ".jsx", ".json"]
         }]
     }
 }
@@ -104,21 +102,13 @@ For example:
 In this style, this option has the following shape as the same expression as above: `{include: [<targetFiles>], replace: [<fromRegExp>, <toString>]}`.
 In addition, we can specify glob patterns to exclude files.
 
-#### tryExtensions
-
-When an import path does not exist, this rule checks whether or not any of `path.js`, `path.json`, and `path.node` exists.
-`tryExtensions` option is the extension list this rule uses at the time.
-
-Default is `[".js", ".json", ".node"]`.
-
 ### Shared Settings
 
 The following options can be set by [shared settings](http://eslint.org/docs/user-guide/configuring.html#adding-shared-settings).
 Several rules have the same option, but we can set this option at once.
 
 - `allowModules`
 - `convertPath`
-- `tryExtensions`
 
 For Example:
 
@@ -130,7 +120,6 @@ For Example:
             "convertPath": {
                 "src/**/*.jsx": ["^src/(.+?)\\.jsx$", "lib/$1.js"]
             },
-            "tryExtensions": [".js", ".jsx", ".json"]
         }
     },
     "rules": {

lib/rules/file-extension-in-import.js

@@ -6,7 +6,6 @@
 
 const path = require("path")
 const fs = require("fs")
-const getTryExtensions = require("../util/get-try-extensions")
 const visitImport = require("../util/visit-import")
 const packageNamePattern = /^(?:@[^/\\]+[/\\])?[^/\\]+$/u
 const corePackageOverridePattern = /^(?:assert|async_hooks|buffer|child_process|cluster|console|constants|crypto|dgram|dns|domain|events|fs|http|http2|https|inspector|module|net|os|path|perf_hooks|process|punycode|querystring|readline|repl|stream|string_decoder|sys|timers|tls|trace_events|tty|url|util|v8|vm|worker_threads|zlib)[/\\]$/u
@@ -53,7 +52,6 @@ module.exports = {
             {
                 type: "object",
                 properties: {
-                    tryExtensions: getTryExtensions.schema,
                 },
                 additionalProperties: {
                     enum: ["always", "never"],
@@ -83,11 +81,7 @@ module.exports = {
             const originalExt = path.extname(name)
             const resolvedExt = path.extname(filePath)
             const existingExts = getExistingExtensions(filePath)
-            if (!resolvedExt && existingExts.length !== 1) {
-                // Ignore if the file extension could not be determined one.
-                return
-            }
-            const ext = resolvedExt || existingExts[0]
+            const ext = resolvedExt || existingExts.join(' or ')
             const style = overrideStyle[ext] || defaultStyle
 
             // Verify.

lib/rules/no-extraneous-import.js

@@ -8,7 +8,6 @@ const checkExtraneous = require("../util/check-extraneous")
 const getAllowModules = require("../util/get-allow-modules")
 const getConvertPath = require("../util/get-convert-path")
 const getResolvePaths = require("../util/get-resolve-paths")
-const getTryExtensions = require("../util/get-try-extensions")
 const visitImport = require("../util/visit-import")
 
 module.exports = {
@@ -29,8 +28,7 @@ module.exports = {
                 properties: {
                     allowModules: getAllowModules.schema,
                     convertPath: getConvertPath.schema,
-                    resolvePaths: getResolvePaths.schema,
-                    tryExtensions: getTryExtensions.schema,
+                    resolvePaths: getResolvePaths.schema
                 },
                 additionalProperties: false,
             },

lib/rules/no-missing-import.js

@@ -7,7 +7,6 @@
 const checkExistence = require("../util/check-existence")
 const getAllowModules = require("../util/get-allow-modules")
 const getResolvePaths = require("../util/get-resolve-paths")
-const getTryExtensions = require("../util/get-try-extensions")
 const visitImport = require("../util/visit-import")
 
 module.exports = {
@@ -27,7 +26,6 @@ module.exports = {
                 type: "object",
                 properties: {
                     allowModules: getAllowModules.schema,
-                    tryExtensions: getTryExtensions.schema,
                     resolvePaths: getResolvePaths.schema,
                 },
                 additionalProperties: false,

lib/rules/no-unpublished-import.js

@@ -8,7 +8,6 @@ const checkPublish = require("../util/check-publish")
 const getAllowModules = require("../util/get-allow-modules")
 const getConvertPath = require("../util/get-convert-path")
 const getResolvePaths = require("../util/get-resolve-paths")
-const getTryExtensions = require("../util/get-try-extensions")
 const visitImport = require("../util/visit-import")
 
 module.exports = {
@@ -29,8 +28,7 @@ module.exports = {
                 properties: {
                     allowModules: getAllowModules.schema,
                     convertPath: getConvertPath.schema,
-                    resolvePaths: getResolvePaths.schema,
-                    tryExtensions: getTryExtensions.schema,
+                    resolvePaths: getResolvePaths.schema
                 },
                 additionalProperties: false,
             },

lib/util/import-target.js

@@ -15,24 +15,51 @@ const {defaultResolve: importResolve} = require("../converted-esm/import-meta-re
  * @param {string} id The id to resolve.
  * @param {object} options The options of node-resolve module.
  * It requires `options.basedir`.
+ * @param {'import' | 'require'} moduleType - whether the target was require-ed or imported
  * @returns {string|null} The resolved path.
  */
-function getFilePath(isModule, id, options) {
-    try {
-        return resolve.sync(id, options)
-    } catch (_err) {
-        try {
-            const {url} = importResolve(id, {
-                    parentURL: pathToFileURL(path.join(options.basedir, 'dummy-file.js')).href,
+function getFilePath(isModule, id, options, moduleType) {
+    if (moduleType === "import") {
+        const paths = options.paths && options.paths.length > 0 ?
+            options.paths.map(p => path.resolve(process.cwd(), p)) :
+            [options.basedir]
+        for (const aPath of paths) {
+            try {
+                const {url} = importResolve(id, {
+                    parentURL: pathToFileURL(path.join(aPath, 'dummy-file.mjs')).href,
                     conditions: ['node', 'import', 'require']
-            })
+                })
+
+                if (url) {
+                    return fileURLToPath(url)
+                }
+            } catch (e) {
+                continue
+            }
+        }
+
+        if (isModule) {
+            return null
+        }
+        return path.resolve((options.paths && options.paths[0]) || options.basedir, id)
+    }
+    else {
+        try {
+            return resolve.sync(id, options)
+        } catch (_err) {
+            try {
+                const {url} = importResolve(id, {
+                        parentURL: pathToFileURL(path.join(options.basedir, 'dummy-file.js')).href,
+                        conditions: ['node', 'require']
+                })
 
-            return fileURLToPath(url)
-        } catch (err) {
-            if (isModule) {
-                return null
+                return fileURLToPath(url)
+            } catch (err) {
+                if (isModule) {
+                    return null
+                }
+                return path.resolve(options.basedir, id)
             }
-            return path.resolve(options.basedir, id)
         }
     }
 }
@@ -63,8 +90,9 @@ module.exports = class ImportTarget {
      * @param {ASTNode} node - The node of a `require()` or a module declaraiton.
      * @param {string} name - The name of an import target.
      * @param {object} options - The options of `node-resolve` module.
+     * @param {'import' | 'require'} moduleType - whether the target was require-ed or imported
      */
-    constructor(node, name, options) {
+    constructor(node, name, options, moduleType) {
         const isModule = !/^(?:[./\\]|\w+:)/u.test(name)
 
         /**
@@ -84,7 +112,7 @@ module.exports = class ImportTarget {
          * If the target is a module and it does not exist then this is `null`.
          * @type {string|null}
          */
-        this.filePath = getFilePath(isModule, name, options)
+        this.filePath = getFilePath(isModule, name, options, moduleType)
 
         /**
          * The module name of this import target.

lib/util/visit-import.js

@@ -55,7 +55,7 @@ module.exports = function visitImport(
             const name = sourceNode && stripImportPathParams(sourceNode.value)
             // Note: "999" arbitrary to check current/future Node.js version
             if (name && (includeCore || !isCoreModule(name, "999"))) {
-                targets.push(new ImportTarget(sourceNode, name, options))
+                targets.push(new ImportTarget(sourceNode, name, options, 'import'))
             }
         },
 

lib/util/visit-require.js

@@ -50,7 +50,7 @@ module.exports = function visitRequire(
                 const name = rawName && stripImportPathParams(rawName)
                 // Note: "999" arbitrary to check current/future Node.js version
                 if (name && (includeCore || !isCoreModule(name, "999"))) {
-                    targets.push(new ImportTarget(targetNode, name, options))
+                    targets.push(new ImportTarget(targetNode, name, options, 'require'))
                 }
             }