feat: Allow for automatic ts mapping detection (#114)

Author: scagood

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

@@ -90,6 +90,42 @@ 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.
+
+#### typescriptExtensionMap
+
+Adds the ability to change the extension mapping when converting between typescript and javascript
+
+You can also use the [typescript compiler jsx options](https://www.typescriptlang.org/tsconfig#jsx) to automatically use the correct mapping.
+
+If this option is left undefined we:
+
+1. Check your `tsconfig.json` `compilerOptions.jsx`
+2. Return the default mapping (jsx = `preserve`)
+
+```js
+// .eslintrc.js
+module.exports = {
+    "settings": {
+        "node": {
+            "typescriptExtensionMap": [
+                [ "", ".js" ],
+                [ ".ts", ".js" ],
+                [ ".cts", ".cjs" ],
+                [ ".mts", ".mjs" ],
+                [ ".tsx", ".jsx" ],
+            ]
+        }
+    },
+    "rules": {
+        "n/file-extension-in-import": "error"
+    }
+}
+```
+
 ## 🔎 Implementation
 
 - [Rule source](../../lib/rules/file-extension-in-import.js)

docs/rules/no-missing-import.md

@@ -73,6 +73,14 @@ Default is `[]`
 
 Adds the ability to change the extension mapping when converting between typescript and javascript
 
+You can also use the [typescript compiler jsx options](https://www.typescriptlang.org/tsconfig#jsx) to automatically use the correct mapping.
+
+If this option is left undefined we:
+
+1. Check the Shared Settings
+2. Check your `tsconfig.json` `compilerOptions.jsx`
+3. Return the default mapping (jsx = `preserve`)
+
 Default is:
 
 ```json
@@ -85,6 +93,10 @@ Default is:
 ]
 ```
 
+#### tsconfigPath
+
+Adds the ability to specify the tsconfig used by the typescriptExtensionMap tool.
+
 ### Shared Settings
 
 The following options can be set by [shared settings](http://eslint.org/docs/user-guide/configuring.html#adding-shared-settings).

docs/rules/no-missing-require.md

@@ -86,6 +86,14 @@ Default is `[".js", ".json", ".node"]`.
 
 Adds the ability to change the extension mapping when converting between typescript and javascript
 
+You can also use the [typescript compiler jsx options](https://www.typescriptlang.org/tsconfig#jsx) to automatically use the correct mapping.
+
+If this option is left undefined we:
+
+1. Check the Shared Settings
+2. Check your `tsconfig.json` `compilerOptions.jsx`
+3. Return the default mapping (jsx = `preserve`)
+
 Default is:
 
 ```json
@@ -98,6 +106,10 @@ Default is:
 ]
 ```
 
+#### tsconfigPath
+
+Adds the ability to specify the tsconfig used by the typescriptExtensionMap tool.
+
 ### Shared Settings
 
 The following options can be set by [shared settings](http://eslint.org/docs/user-guide/configuring.html#adding-shared-settings).

lib/rules/no-missing-import.js

@@ -7,6 +7,7 @@
 const { checkExistence, messages } = require("../util/check-existence")
 const getAllowModules = require("../util/get-allow-modules")
 const getResolvePaths = require("../util/get-resolve-paths")
+const getTSConfig = require("../util/get-tsconfig")
 const getTypescriptExtensionMap = require("../util/get-typescript-extension-map")
 const visitImport = require("../util/visit-import")
 
@@ -28,6 +29,7 @@ module.exports = {
                     allowModules: getAllowModules.schema,
                     resolvePaths: getResolvePaths.schema,
                     typescriptExtensionMap: getTypescriptExtensionMap.schema,
+                    tsconfigPath: getTSConfig.schema,
                 },
                 additionalProperties: false,
             },

lib/rules/no-missing-require.js

@@ -7,6 +7,7 @@
 const { checkExistence, messages } = require("../util/check-existence")
 const getAllowModules = require("../util/get-allow-modules")
 const getResolvePaths = require("../util/get-resolve-paths")
+const getTSConfig = require("../util/get-tsconfig")
 const getTryExtensions = require("../util/get-try-extensions")
 const getTypescriptExtensionMap = require("../util/get-typescript-extension-map")
 const visitRequire = require("../util/visit-require")
@@ -30,6 +31,7 @@ module.exports = {
                     tryExtensions: getTryExtensions.schema,
                     resolvePaths: getResolvePaths.schema,
                     typescriptExtensionMap: getTypescriptExtensionMap.schema,
+                    tsconfigPath: getTSConfig.schema,
                 },
                 additionalProperties: false,
             },

lib/util/get-tsconfig.js

@@ -0,0 +1,31 @@
+"use strict"
+
+const { getTsconfig, parseTsconfig } = require("get-tsconfig")
+const fsCache = new Map()
+
+/**
+ * Attempts to get the ExtensionMap from the tsconfig given the path to the tsconfig file.
+ *
+ * @param {string} filename - The path to the tsconfig.json file
+ * @returns {import("get-tsconfig").TsConfigJsonResolved}
+ */
+function getTSConfig(filename) {
+    return parseTsconfig(filename, fsCache)
+}
+
+/**
+ * Attempts to get the ExtensionMap from the tsconfig of a given file.
+ *
+ * @param {string} filename - The path to the file we need to find the tsconfig.json of
+ * @returns {import("get-tsconfig").TsConfigResult}
+ */
+function getTSConfigForFile(filename) {
+    return getTsconfig(filename, "tsconfig.json", fsCache)
+}
+
+module.exports = {
+    getTSConfig,
+    getTSConfigForFile,
+}
+
+module.exports.schema = { type: "string" }

lib/util/get-typescript-extension-map.js

@@ -1,13 +1,31 @@
 "use strict"
 
+const { getTSConfig, getTSConfigForFile } = require("./get-tsconfig")
+
 const DEFAULT_MAPPING = normalise([
+    ["", ".js"],
+    [".ts", ".js"],
+    [".cts", ".cjs"],
+    [".mts", ".mjs"],
+    [".tsx", ".js"],
+])
+
+const PRESERVE_MAPPING = normalise([
     ["", ".js"],
     [".ts", ".js"],
     [".cts", ".cjs"],
     [".mts", ".mjs"],
     [".tsx", ".jsx"],
 ])
 
+const tsConfigMapping = {
+    react: DEFAULT_MAPPING, // Emit .js files with JSX changed to the equivalent React.createElement calls
+    "react-jsx": DEFAULT_MAPPING, // Emit .js files with the JSX changed to _jsx calls
+    "react-jsxdev": DEFAULT_MAPPING, // Emit .js files with the JSX changed to _jsx calls
+    "react-native": DEFAULT_MAPPING, // Emit .js files with the JSX unchanged
+    preserve: PRESERVE_MAPPING, // Emit .jsx files with the JSX unchanged
+}
+
 /**
  * @typedef {Object} ExtensionMap
  * @property {Record<string, string>} forward Convert from typescript to javascript
@@ -28,6 +46,22 @@ function normalise(typescriptExtensionMap) {
     return { forward, backward }
 }
 
+/**
+ * Attempts to get the ExtensionMap from the resolved tsconfig.
+ *
+ * @param {import("get-tsconfig").TsConfigJsonResolved} [tsconfig] - The resolved tsconfig
+ * @returns {ExtensionMap} The `typescriptExtensionMap` value, or `null`.
+ */
+function getMappingFromTSConfig(tsconfig) {
+    const jsx = tsconfig?.compilerOptions?.jsx
+
+    if ({}.hasOwnProperty.call(tsConfigMapping, jsx)) {
+        return tsConfigMapping[jsx]
+    }
+
+    return null
+}
+
 /**
  * Gets `typescriptExtensionMap` property from a given option object.
  *
@@ -36,46 +70,82 @@ function normalise(typescriptExtensionMap) {
  */
 function get(option) {
     if (
-        option &&
-        option.typescriptExtensionMap &&
-        Array.isArray(option.typescriptExtensionMap)
+        {}.hasOwnProperty.call(tsConfigMapping, option?.typescriptExtensionMap)
     ) {
+        return tsConfigMapping[option.typescriptExtensionMap]
+    }
+
+    if (Array.isArray(option?.typescriptExtensionMap)) {
         return normalise(option.typescriptExtensionMap)
     }
 
+    if (option?.tsconfigPath) {
+        return getMappingFromTSConfig(getTSConfig(option?.tsconfigPath))
+    }
+
     return null
 }
 
+/**
+ * Attempts to get the ExtensionMap from the tsconfig of a given file.
+ *
+ * @param {string} filename - The filename we're getting from
+ * @returns {ExtensionMap} The `typescriptExtensionMap` value, or `null`.
+ */
+function getFromTSConfigFromFile(filename) {
+    return getMappingFromTSConfig(getTSConfigForFile(filename)?.config)
+}
+
 /**
  * Gets "typescriptExtensionMap" setting.
  *
- * 1. This checks `options` property, then returns it if exists.
- * 2. This checks `settings.n` | `settings.node` property, then returns it if exists.
- * 3. This returns `DEFAULT_MAPPING`.
+ * 1. This checks `options.typescriptExtensionMap`, if its an array then it gets returned.
+ * 2. This checks `options.typescriptExtensionMap`, if its a string, convert to the correct mapping.
+ * 3. This checks `settings.n.typescriptExtensionMap`, if its an array then it gets returned.
+ * 4. This checks `settings.node.typescriptExtensionMap`, if its an array then it gets returned.
+ * 5. This checks `settings.n.typescriptExtensionMap`, if its a string, convert to the correct mapping.
+ * 6. This checks `settings.node.typescriptExtensionMap`, if its a string, convert to the correct mapping.
+ * 7. This checks for a `tsconfig.json` `config.compilerOptions.jsx` property, if its a string, convert to the correct mapping.
+ * 8. This returns `PRESERVE_MAPPING`.
  *
- * @param {import('eslint').Rule.RuleContext} context - The rule context.
+ * @param {import("eslint").Rule.RuleContext} context - The rule context.
  * @returns {string[]} A list of extensions.
  */
 module.exports = function getTypescriptExtensionMap(context) {
     return (
-        get(context.options && context.options[0]) ||
-        get(
-            context.settings && (context.settings.n || context.settings.node)
+        get(context.options?.[0]) ||
+        get(context.settings?.n ?? context.settings?.node) ||
+        getFromTSConfigFromFile(
+            // eslint ^8
+            context.physicalFilename ??
+                // eslint ^7.28 (deprecated ^8)
+                context.getPhysicalFilename?.() ??
+                // eslint ^8 (if physicalFilename undefined)
+                context.filename ??
+                // eslint ^7 (deprecated ^8)
+                context.getFilename?.()
         ) ||
-        // TODO: Detect tsconfig.json here
-        DEFAULT_MAPPING
+        PRESERVE_MAPPING
     )
 }
 
 module.exports.schema = {
-    type: "array",
-    items: {
-        type: "array",
-        prefixItems: [
-            { type: "string", pattern: "^(?:|\\.\\w+)$" },
-            { type: "string", pattern: "^\\.\\w+$" },
-        ],
-        additionalItems: false,
-    },
-    uniqueItems: true,
+    oneOf: [
+        {
+            type: "array",
+            items: {
+                type: "array",
+                prefixItems: [
+                    { type: "string", pattern: "^(?:|\\.\\w+)$" },
+                    { type: "string", pattern: "^\\.\\w+$" },
+                ],
+                additionalItems: false,
+            },
+            uniqueItems: true,
+        },
+        {
+            type: "string",
+            enum: Object.keys(tsConfigMapping),
+        },
+    ],
 }

package.json

@@ -17,6 +17,7 @@
         "@eslint-community/eslint-utils": "^4.4.0",
         "builtins": "^5.0.1",
         "eslint-plugin-es-x": "^7.1.0",
+        "get-tsconfig": "^4.7.0",
         "ignore": "^5.2.4",
         "is-core-module": "^2.12.1",
         "minimatch": "^3.1.2",

tests/fixtures/no-missing/ts-extends/base.tsconfig.json

@@ -0,0 +1,5 @@
+{
+    "compilerOptions": {
+        "jsx": "react"
+    }
+}