Resolve customMatcher issues

src/helpers/__tests__/createMatchers.test.ts

@@ -0,0 +1,23 @@
+import { createMatchers } from '../createMatchers';
+
+describe('utils / createMatchers', () => {
+  it('should match `customMatcher` regexp', () => {
+    const options: IOptions = { customMatcher: '\\.css$' };
+    const { isCSS, isRelativeCSS } = createMatchers(options);
+
+    expect(isCSS('./myfile.css')).toBe(true);
+    expect(isCSS('./myfile.m.css')).toBe(true);
+    expect(isCSS('./myfile.scss')).toBe(false);
+    expect(isRelativeCSS('../folder/myfile.css')).toBe(true);
+    expect(isRelativeCSS('../folder/myfile.m.css')).toBe(true);
+    expect(isRelativeCSS('../folders/myfile.scss')).toBe(false);
+  });
+
+  it('should handle bad `customMatcher` regexp', () => {
+    const options: IOptions = { customMatcher: '$([a' };
+    const { isCSS, isRelativeCSS } = createMatchers(options);
+
+    expect(isCSS('./myfile.module.css')).toBe(true);
+    expect(isRelativeCSS('../folders/myfile.module.scss')).toBe(true);
+  });
+});

src/helpers/__tests__/cssExtensions.test.ts

@@ -1,7 +1,9 @@
-import { isCSS, isRelativeCSS } from '../cssExtensions';
+import { createIsCSS, createIsRelativeCSS } from '../cssExtensions';
 
 describe('utils / cssExtensions', () => {
   describe('isCSS', () => {
+    const isCSS = createIsCSS();
+
     it('should match CSS module extensions', () => {
       expect(isCSS('./myfile.module.scss')).toBe(true);
       expect(isCSS('./myfile.module.sass')).toBe(true);
@@ -17,6 +19,9 @@ describe('utils / cssExtensions', () => {
   });
 
   describe('isRelativeCSS', () => {
+    const isCSS = createIsCSS();
+    const isRelativeCSS = createIsRelativeCSS(isCSS);
+
     it('should match relative CSS modules', () => {
       expect(isRelativeCSS('./myfile.module.css')).toBe(true);
       expect(isRelativeCSS('../folder/myfile.module.css')).toBe(true);

src/helpers/createMatchers.ts

@@ -0,0 +1,20 @@
+import { createIsCSS, createIsRelativeCSS } from './cssExtensions';
+
+export const createMatchers = (options: IOptions = {}) => {
+  // Allow custom matchers to be used, and handle bad matcher patterns.
+  let isCSS = createIsCSS();
+  try {
+    const { customMatcher } = options;
+    if (customMatcher) {
+      const customMatcherRegExp = new RegExp(customMatcher);
+      isCSS = createIsCSS(customMatcherRegExp);
+    }
+  } catch (e) {
+    // TODO: Provide error/warning to user.
+  }
+
+  // Create the relative CSS checker.
+  const isRelativeCSS = createIsRelativeCSS(isCSS);
+
+  return { isCSS, isRelativeCSS };
+};

src/helpers/cssExtensions.ts

@@ -1,7 +1,10 @@
-const isRelative = (fileName: string) => /^\.\.?($|[\\/])/.test(fileName);
+export type isCSSFn = (fileName: string) => boolean;
+const DEFAULT_REGEXP = /\.module\.(sa|sc|c)ss$/;
 
-export const isCSS = (fileName: string) =>
-  /\.module\.(sa|sc|c)ss$/.test(fileName);
+const isRelative = (fileName: string) => /^\.\.?($|[\\/])/.test(fileName);
 
-export const isRelativeCSS = (fileName: string) =>
+export const createIsCSS = (
+  customMatcher: RegExp = DEFAULT_REGEXP,
+): isCSSFn => (fileName: string) => customMatcher.test(fileName);
+export const createIsRelativeCSS = (isCSS: isCSSFn) => (fileName: string) =>
   isCSS(fileName) && isRelative(fileName);

src/index.ts

@@ -1,23 +1,18 @@
 import * as path from 'path';
 import * as ts_module from 'typescript/lib/tsserverlibrary';
-import { isCSS as _isCSS, isRelativeCSS } from './helpers/cssExtensions';
+import { createMatchers } from './helpers/createMatchers';
+import { isCSSFn } from './helpers/cssExtensions';
 import { getDtsSnapshot } from './helpers/cssSnapshots';
 
 function init({ typescript: ts }: { typescript: typeof ts_module }) {
-  let isCSS = _isCSS;
+  let _isCSS: isCSSFn;
   function create(info: ts.server.PluginCreateInfo) {
     // User options for plugin.
     const options: IOptions = info.config.options || {};
 
-    // Allow custom matchers to be used, handling bad matcher patterns;
-    try {
-      const { customMatcher } = options;
-      if (customMatcher) {
-        isCSS = (fileName) => new RegExp(customMatcher).test(fileName);
-      }
-    } catch (e) {
-      // TODO: Provide error/warning to user.
-    }
+    // Create matchers using options object.
+    const { isCSS, isRelativeCSS } = createMatchers(options);
+    _isCSS = isCSS;
 
     // Creates new virtual source files for the CSS modules.
     const _createLanguageServiceSourceFile = ts.createLanguageServiceSourceFile;
@@ -97,7 +92,7 @@ function init({ typescript: ts }: { typescript: typeof ts_module }) {
   }
 
   function getExternalFiles(project: ts_module.server.ConfiguredProject) {
-    return project.getFileNames().filter(isCSS);
+    return project.getFileNames().filter(_isCSS);
   }
 
   return { create, getExternalFiles };