[FEAT] #2 added support for tsconfig paths

Author: bradzacher

.gitignore

@@ -1 +1,3 @@
 node_modules
+yarn-error.log
+yarn.lock

README.md

@@ -1,23 +1,23 @@
 # eslint-import-resolver-typescript
 
-This plugin allows you to use `eslint-plugin-import` with `.ts` and `.tsx` files.
+This plugin allows you to resolve `typescript` files with `eslint-plugin-import`.
+
+The resolution respects the [`paths`](https://www.typescriptlang.org/docs/handbook/module-resolution.html#path-mapping) you have defined in your `tsconfig.json`.
 
 ![](screenshot.png)
 
 ## Installation
 
-```
+```bash
 npm install --save-dev eslint-import-resolver-typescript
 ```
 
 Add the following to your eslint config:
 
-```
+```JSON
 "settings": {
   "import/resolver": {
-    "node": true,
-    "eslint-import-resolver-typescript": true
+    "typescript": true
   }
 }
 ```
-

index.js

@@ -1,26 +1,76 @@
-const resolve = require('resolve');
-const path = require('path');
-
-function opts(file, config) {
-  return Object.assign(
-    { extensions: ['.ts', '.tsx', '.d.ts'] },
-    config,
-    // path.resolve will handle paths relative to CWD
-    { basedir: path.dirname(path.resolve(file)) }
-  );
-}
+'use strict'
 
-module.exports = {
-  interfaceVersion: 2,
-  resolve: function(source, file, config) {
-    if (resolve.isCore(source)) {
-      return { found: true, path: null };
+const path = require('path')
+const resolve = require('resolve')
+const tsconfigPaths = require('tsconfig-paths')
+const debug = require('debug')
+
+const log = debug('eslint-import-resolver-typescript')
+
+/**
+ * @param {string} source the module to resolve; i.e './some-module'
+ * @param {string} file the importing file's full path; i.e. '/usr/local/bin/file.js'
+ */
+function resolveFile(source, file, config) {
+  log('looking for:', source)
+
+  // don't worry about core node modules
+  if (resolve.isCore(source)) {
+    log('matched core:', source)
+
+    return {
+      found: true,
+      path: null,
     }
+  }
+
+  // setup tsconfig-paths
+  const searchStart = config.directory || process.cwd()
+  const configLoaderResult = tsconfigPaths.loadConfig(searchStart)
+  if (configLoaderResult.resultType !== 'success') {
+    throw new Error(`Unable to find tsconfig in ${searchStart}: ${configLoaderResult.message}`)
+  }
+  const matchPath = tsconfigPaths.createMatchPath(
+    configLoaderResult.absoluteBaseUrl,
+    configLoaderResult.paths,
+  )
+
+  // look for files based on setup tsconfig "paths"
+  const extensions = Object.keys(require.extensions).concat('.ts', '.tsx', '.d.ts')
+  const foundTsPath = matchPath(
+    source,
+    undefined,
+    undefined,
+    extensions,
+  )
 
-    try {
-      return { found: true, path: resolve.sync(source, opts(file, config)) };
-    } catch (err) {
-      return { found: false };
+  if (foundTsPath) {
+    log('matched ts path:', foundTsPath)
+  }
+
+  // note that even if we match via tsconfig-paths, we still need to do a final resolve
+  const foundNodePath = resolve.sync(foundTsPath || source, {
+    extensions,
+    basedir: path.dirname(path.resolve(file)),
+  })
+
+  if (foundNodePath) {
+    log('matched node path:', foundNodePath)
+
+    return {
+      found: true,
+      path: foundNodePath,
     }
-  },
-};
+  }
+
+  log('didnt find', source)
+
+  return {
+    found: false
+  }
+}
+
+module.exports = {
+  interfaceVersion: 2,
+  resolve: resolveFile,
+}

package-lock.json

@@ -20,6 +20,9 @@
   "author": "Alex Gorbatchev <alex.gorbatchev@gmail.com>",
   "license": "ISC",
   "dependencies": {
-    "resolve": "^1.4.0"
-  }
+    "debug": "^4.0.1",
+    "resolve": "^1.4.0",
+    "tsconfig-paths": "^3.6.0"
+  },
+  "devDependencies": {}
 }