feat: use typescript

.c8rc.json

@@ -1,4 +1,4 @@
 {
-    "include": ["src/**/*.mjs"],
+    "include": ["src/**/*.ts"],
     "reporter": ["lcov", "text-summary"]
 }

.eslintignore

@@ -7,3 +7,4 @@
 !.vitepress
 /docs/.vitepress/dist
 /docs/.vitepress/cache
+/dist

.eslintrc.js

@@ -4,18 +4,34 @@
 module.exports = {
     root: true,
     extends: ["plugin:@eslint-community/mysticatea/es2020"],
+    parserOptions: {
+        project: "./tsconfig.json",
+    },
     rules: {
         "@eslint-community/mysticatea/prettier": "off",
+        "@eslint-community/mysticatea/ts/naming-convention": "off",
+        "@eslint-community/mysticatea/ts/prefer-readonly-parameter-types":
+            "off",
+        "@eslint-community/mysticatea/node/no-missing-import": [
+            "error",
+            {
+                allowModules: ["estree", "unbuild"],
+            },
+        ],
+    },
+    settings: {
+        node: {
+            tryExtensions: [".js", ".json", ".mjs", ".node", ".ts", ".tsx"],
+        },
     },
     overrides: [
         {
-            files: ["src/**/*.mjs", "test/**/*.mjs"],
+            files: ["src/**/*.ts", "test/**/*.ts"],
             extends: ["plugin:@eslint-community/mysticatea/+modules"],
             rules: {
                 "init-declarations": "off",
-
-                "@eslint-community/mysticatea/node/no-unsupported-features/es-syntax":
-                    ["error", { ignores: ["modules"] }],
+                "no-duplicate-imports": "off",
+                "no-shadow": "off",
             },
         },
     ],

.gitignore

@@ -5,3 +5,4 @@
 /node_modules
 /index.*
 /test.*
+/dist

.vscode/settings.json

@@ -1,9 +1,15 @@
 {
+    "eslint.validate": ["javascript", "typescript"],
     "[javascript]": {
         "editor.defaultFormatter": "esbenp.prettier-vscode",
         "editor.formatOnSave": true,
         "editor.codeActionsOnSave": ["source.organizeImports", "source.fixAll"]
     },
+    "[typescript]": {
+        "editor.defaultFormatter": "esbenp.prettier-vscode",
+        "editor.formatOnSave": true,
+        "editor.codeActionsOnSave": ["source.organizeImports", "source.fixAll"]
+    },
     "[json]": {
         "editor.defaultFormatter": "esbenp.prettier-vscode",
         "editor.formatOnSave": true,

build.config.ts

@@ -0,0 +1,14 @@
+import { defineBuildConfig } from "unbuild"
+
+export default defineBuildConfig({
+    externals: ["estree"],
+    hooks: {
+        "rollup:options"(_ctx, options) {
+            for (const output of [options.output].flat()) {
+                if (output!.format === "cjs") {
+                    output!.exports = "named"
+                }
+            }
+        },
+    },
+})

package.json

@@ -18,49 +18,56 @@
     "sideEffects": false,
     "exports": {
         ".": {
-            "import": "./index.mjs",
-            "require": "./index.js"
+            "import": "./dist/index.mjs",
+            "require": "./dist/index.cjs"
         },
         "./package.json": "./package.json"
     },
-    "main": "index",
-    "module": "index.mjs",
+    "main": "./dist/index.cjs",
+    "module": "./dist/index.mjs",
+    "types": "./dist/index.d.ts",
     "files": [
-        "index.*"
+        "dist"
     ],
     "scripts": {
         "prebuild": "npm run -s clean",
-        "build": "rollup -c",
+        "build": "unbuild",
         "clean": "rimraf .nyc_output coverage index.*",
         "coverage": "opener ./coverage/lcov-report/index.html",
         "docs:build": "vitepress build docs",
         "docs:watch": "vitepress dev docs",
         "format": "npm run -s format:prettier -- --write",
         "format:prettier": "prettier .",
         "format:check": "npm run -s format:prettier -- --check",
-        "lint": "eslint .",
-        "test": "c8 mocha --reporter dot \"test/*.mjs\"",
+        "lint": "tsc && eslint .",
+        "test": "c8 mocha --require=esbuild-register --reporter dot \"test/*.ts\"",
         "preversion": "npm test && npm run -s build",
         "postversion": "git push && git push --tags",
         "prewatch": "npm run -s clean",
-        "watch": "warun \"{src,test}/**/*.mjs\" -- npm run -s test:mocha"
+        "watch": "warun \"{src,test}/**/*.ts\" -- npm run -s test:mocha"
     },
     "dependencies": {
         "eslint-visitor-keys": "^3.3.0"
     },
     "devDependencies": {
         "@eslint-community/eslint-plugin-mysticatea": "^15.2.0",
+        "@types/eslint": "^8.21.0",
+        "@types/estree": "^1.0.0",
+        "@types/mocha": "^10.0.1",
+        "@types/node": "^18.11.18",
+        "@typescript-eslint/types": "^5.50.0",
         "c8": "^7.12.0",
         "dot-prop": "^6.0.1",
+        "esbuild-register": "^3.4.2",
         "eslint": "^8.28.0",
         "mocha": "^9.2.2",
         "npm-run-all": "^4.1.5",
         "opener": "^1.5.2",
         "prettier": "2.8.4",
         "rimraf": "^3.0.2",
-        "rollup": "^2.79.1",
-        "rollup-plugin-sourcemaps": "^0.6.3",
         "semver": "^7.3.8",
+        "typescript": "^4.9.5",
+        "unbuild": "^1.1.1",
         "vitepress": "^1.0.0-alpha.40",
         "warun": "^1.0.0"
     },

src/find-variable.ts

@@ -0,0 +1,34 @@
+import type { Scope } from "eslint"
+import type * as ESTree from "estree"
+import { getInnermostScope } from "./get-innermost-scope"
+
+/**
+ * Find the variable of a given name.
+ * @param initialScope The scope to start finding.
+ * @param nameOrNode The variable name to find. If this is a Node object then it should be an Identifier node.
+ * @returns The found variable or null.
+ */
+export function findVariable(
+    initialScope: Scope.Scope,
+    nameOrNode: ESTree.Identifier | string,
+): Scope.Variable | null {
+    let name = ""
+    let scope: Scope.Scope | null = initialScope
+
+    if (typeof nameOrNode === "string") {
+        name = nameOrNode
+    } else {
+        name = nameOrNode.name
+        scope = getInnermostScope(scope, nameOrNode)
+    }
+
+    while (scope != null) {
+        const variable = scope.set.get(name)
+        if (variable != null) {
+            return variable
+        }
+        scope = scope.upper
+    }
+
+    return null
+}

src/get-function-head-location.ts

@@ -0,0 +1,56 @@
+import type { SourceCode } from "eslint"
+import type * as ESTree from "estree"
+import { getParent } from "./get-parent"
+import { isArrowToken, isOpeningParenToken } from "./token-predicate"
+
+/**
+ * Get the `(` token of the given function node.
+ * @param node - The function node to get.
+ * @param sourceCode - The source code object to get tokens.
+ * @returns `(` token.
+ */
+function getOpeningParenOfParams(
+    node: ESTree.Function,
+    sourceCode: SourceCode,
+) {
+    return node.type !== "ArrowFunctionExpression" && node.id
+        ? sourceCode.getTokenAfter(node.id, isOpeningParenToken)!
+        : sourceCode.getFirstToken(node, isOpeningParenToken)!
+}
+
+/**
+ * Get the location of the given function node for reporting.
+ * @param node - The function node to get.
+ * @param sourceCode - The source code object to get tokens.
+ * @returns The location of the function node for reporting.
+ */
+export function getFunctionHeadLocation(
+    node: ESTree.Function,
+    sourceCode: SourceCode,
+): ESTree.SourceLocation {
+    const parent = getParent(node)!
+    let start: ESTree.Position | null = null
+    let end: ESTree.Position | null = null
+
+    if (node.type === "ArrowFunctionExpression") {
+        const arrowToken = sourceCode.getTokenBefore(node.body, isArrowToken)!
+
+        start = arrowToken.loc.start
+        end = arrowToken.loc.end
+    } else if (
+        parent.type === "Property" ||
+        parent.type === "MethodDefinition" ||
+        parent.type === "PropertyDefinition"
+    ) {
+        start = parent.loc!.start
+        end = getOpeningParenOfParams(node, sourceCode).loc.start
+    } else {
+        start = node.loc!.start
+        end = getOpeningParenOfParams(node, sourceCode).loc.start
+    }
+
+    return {
+        start: { ...start },
+        end: { ...end },
+    }
+}

src/get-function-name-with-kind.mjs → src/get-function-name-with-kind.ts

@@ -1,14 +1,20 @@
-import { getPropertyName } from "./get-property-name.mjs"
+import type { SourceCode } from "eslint"
+import type * as ESTree from "estree"
+import { getParent } from "./get-parent"
+import { getPropertyName } from "./get-property-name"
 
 /**
  * Get the name and kind of the given function node.
- * @param {ASTNode} node - The function node to get.
- * @param {SourceCode} [sourceCode] The source code object to get the code of computed property keys.
- * @returns {string} The name and kind of the function node.
+ * @param node - The function node to get.
+ * @param sourceCode The source code object to get the code of computed property keys.
+ * @returns The name and kind of the function node.
  */
 // eslint-disable-next-line complexity
-export function getFunctionNameWithKind(node, sourceCode) {
-    const parent = node.parent
+export function getFunctionNameWithKind(
+    node: ESTree.Function,
+    sourceCode?: SourceCode,
+): string {
+    const parent = getParent(node)!
     const tokens = []
     const isObjectMethod = parent.type === "Property" && parent.value === node
     const isClassMethod =
@@ -68,7 +74,7 @@ export function getFunctionNameWithKind(node, sourceCode) {
                 }
             }
         }
-    } else if (node.id) {
+    } else if (node.type !== "ArrowFunctionExpression" && node.id) {
         tokens.push(`'${node.id.name}'`)
     } else if (
         parent.type === "VariableDeclarator" &&