feat: add startsWith option

BREAKING_CHANGE

README.md

@@ -26,3 +26,7 @@ module.exports = {
   // ... other configs
 }
 ```
+
+## Options
+
+- __startsWith:__ ensures that all the replaced paths (keys in the tsconfig) happen at the beginning of the path. is `true` by default.

src/index.test.ts

@@ -6,8 +6,18 @@ describe('test lib', () => {
     tsconfigPathsJestMapper(path.resolve(__dirname, '../test/right-config'));
   })
 
-  it('should convert paths to jest moduleNameMapper', () => {
+  it('should convert paths to jest moduleNameMapper when they start with pattern', () => {
     const mappers = tsconfigPathsJestMapper(path.resolve(__dirname, '../test/right-config'));
+    expect(mappers).toEqual({
+      "^\\$main": "<rootDir>/src/index.ts",
+      "^\\$components(/?.*)": "<rootDir>/src/components$1",
+      "^\\$errors(/?.*)": "<rootDir>/src/errors$1",
+      "^@app(/?.*)": "<rootDir>/src/app$1"
+    })
+  })
+
+  it('should convert paths to jest moduleNameMapper everywhere', () => {
+    const mappers = tsconfigPathsJestMapper(path.resolve(__dirname, '../test/right-config'), { startsWith: false });
     expect(mappers).toEqual({
       "\\$main": "<rootDir>/src/index.ts",
       "\\$components(/?.*)": "<rootDir>/src/components$1",

src/index.ts

@@ -6,7 +6,7 @@ function escapeRegExp(text: string) {
   return text.replace(/[-[\]{}()+?.,\\^$|#\s]/g, '\\$&');
 }
 
-export const getJestMappersFromTSConfig = (tsconfigPath: string) => {
+export const getJestMappersFromTSConfig = (tsconfigPath: string, options: { startsWith: boolean } = { startsWith: true }) => {
   const { config } = loadSync('', tsconfigPath);
   if (!config.compilerOptions || !config.compilerOptions.paths) {
     throw new Error('paths field not found in tsconfig compiler options');
@@ -28,7 +28,10 @@ export const getJestMappersFromTSConfig = (tsconfigPath: string) => {
     }
 
     const [ value ] = valueArray;
-    const source = escapeRegExp(key).replace(/\/\*/, "(/?.*)");
+    let source = escapeRegExp(key).replace(/\/\*/, "(/?.*)");
+    if(options.startsWith) {
+      source = `^${source}`;
+    }
     const path = `<rootDir>/${value.replace(/\/?\*/, "$1")}`;
     moduleNameMapper[source] = path;
   }