fix(utils): pathsToModuleNameMapper resolve path mapping with path.join

e2e/__cases__/utils/src/foo/bar.ts

@@ -0,0 +1 @@
+export const a = 1;

e2e/__cases__/utils/ts-jest-utils.spec.ts

@@ -1,8 +1,13 @@
 import * as utils from 'ts-jest/utils'
+import { compilerOptions } from './tsconfig.json';
 
 test('utils', () => {
   expect(Object.keys(utils)).toEqual(['mocked', 'createJestPreset', 'pathsToModuleNameMapper'])
   expect(typeof utils.mocked).toBe('function')
   expect(typeof utils.createJestPreset).toBe('function')
   expect(typeof utils.pathsToModuleNameMapper).toBe('function')
 })
+
+test('pathsToModuleNameMapper', () => {
+  expect(utils.pathsToModuleNameMapper(compilerOptions.paths, { prefix: compilerOptions.baseUrl } )).toEqual({'^foo/(.*)$': 'src/foo/$1'})
+})

e2e/__cases__/utils/tsconfig.json

@@ -0,0 +1,14 @@
+{
+  "compilerOptions": {
+    "baseUrl": "src",
+    "target": "ES5",
+    "module": "CommonJS",
+    "resolveJsonModule": true,
+    "paths": {
+      "foo/*": ["foo/*"]
+    }
+  },
+  "exclude": [
+    "node_modules"
+  ]
+}

src/config/__snapshots__/paths-to-module-name-mapper.spec.ts.snap

@@ -0,0 +1,39 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`pathsToModuleNameMapper should convert tsconfig mapping with given prefix: <rootDir>/ 1`] = `
+Object {
+  "^api/(.*)$": "<rootDir>/src/api/$1",
+  "^client$": Array [
+    "<rootDir>/src/client",
+    "<rootDir>/src/client/index",
+  ],
+  "^log$": "<rootDir>/src/utils/log",
+  "^mocks/(.*)$": "<rootDir>/test/mocks/$1",
+  "^server$": "<rootDir>/src/server",
+  "^test/(.*)$": "<rootDir>/test/$1",
+  "^test/(.*)/mock$": Array [
+    "<rootDir>/test/mocks/$1",
+    "<rootDir>/test/__mocks__/$1",
+  ],
+  "^util/(.*)$": "<rootDir>/src/utils/$1",
+}
+`;
+
+exports[`pathsToModuleNameMapper should convert tsconfig mapping with given prefix: foo 1`] = `
+Object {
+  "^api/(.*)$": "foo/src/api/$1",
+  "^client$": Array [
+    "foo/src/client",
+    "foo/src/client/index",
+  ],
+  "^log$": "foo/src/utils/log",
+  "^mocks/(.*)$": "foo/test/mocks/$1",
+  "^server$": "foo/src/server",
+  "^test/(.*)$": "foo/test/$1",
+  "^test/(.*)/mock$": Array [
+    "foo/test/mocks/$1",
+    "foo/test/__mocks__/$1",
+  ],
+  "^util/(.*)$": "foo/src/utils/$1",
+}
+`;

src/config/paths-to-module-name-mapper.spec.ts

@@ -14,7 +14,7 @@ const tsconfigMap = {
 }
 
 describe('pathsToModuleNameMapper', () => {
-  it('should convert tsconfig mapping', () => {
+  it('should convert tsconfig mapping with no given prefix', () => {
     expect(pathsToModuleNameMapper(tsconfigMap)).toMatchInlineSnapshot(`
       Object {
         "^api/(.*)$": "src/api/$1",
@@ -35,25 +35,8 @@ describe('pathsToModuleNameMapper', () => {
     `)
   })
 
-  it('should use the given prefix', () => {
-    expect(pathsToModuleNameMapper(tsconfigMap, { prefix: '<rootDir>/' })).toMatchInlineSnapshot(`
-      Object {
-        "^api/(.*)$": "<rootDir>/src/api/$1",
-        "^client$": Array [
-          "<rootDir>/src/client",
-          "<rootDir>/src/client/index",
-        ],
-        "^log$": "<rootDir>/src/utils/log",
-        "^mocks/(.*)$": "<rootDir>/test/mocks/$1",
-        "^server$": "<rootDir>/src/server",
-        "^test/(.*)$": "<rootDir>/test/$1",
-        "^test/(.*)/mock$": Array [
-          "<rootDir>/test/mocks/$1",
-          "<rootDir>/test/__mocks__/$1",
-        ],
-        "^util/(.*)$": "<rootDir>/src/utils/$1",
-      }
-    `)
+  it.each(['<rootDir>/', 'foo'])('should convert tsconfig mapping with given prefix', (prefix) => {
+    expect(pathsToModuleNameMapper(tsconfigMap, { prefix })).toMatchSnapshot(prefix)
   })
 
   it('should warn about mapping it cannot handle', () => {

src/config/paths-to-module-name-mapper.ts

@@ -4,6 +4,8 @@ import type { CompilerOptions } from 'typescript'
 
 import { rootLogger } from '../utils/logger'
 import { Errors, interpolate } from '../utils/messages'
+import { join } from 'path'
+import { normalizeSlashes } from '../utils/normalize-slashes'
 
 type TsPathMapping = Exclude<CompilerOptions['paths'], undefined>
 type JestPathMapping = Config.InitialOptions['moduleNameMapper']
@@ -25,22 +27,22 @@ export const pathsToModuleNameMapper = (
     // check that we have only one target path
     if (toPaths.length === 0) {
       logger.warn(interpolate(Errors.NotMappingPathWithEmptyMap, { path: fromPath }))
+
       continue
     }
 
     // split with '*'
     const segments = fromPath.split(/\*/g)
     if (segments.length === 1) {
-      const paths = toPaths.map((target) => `${prefix}${target}`)
+      const paths = toPaths.map((target) => normalizeSlashes(join(prefix, target)))
       pattern = `^${escapeRegex(fromPath)}$`
       jestMap[pattern] = paths.length === 1 ? paths[0] : paths
     } else if (segments.length === 2) {
-      const paths = toPaths.map((target) => `${prefix}${target.replace(/\*/g, '$1')}`)
+      const paths = toPaths.map((target) => normalizeSlashes(join(prefix, target.replace(/\*/g, '$1'))))
       pattern = `^${escapeRegex(segments[0])}(.*)${escapeRegex(segments[1])}$`
       jestMap[pattern] = paths.length === 1 ? paths[0] : paths
     } else {
       logger.warn(interpolate(Errors.NotMappingMultiStarPath, { path: fromPath }))
-      continue
     }
   }