(fix): declarationMaps (*.d.ts.map) should have correct sources

- when declarationDir is set, `sources` gets set correctly, but
  otherwise its relative path will be incorrect
  - so always set declarationDir to paths.appDist

src/createRollupConfig.ts

@@ -155,6 +155,7 @@ export async function createRollupConfig(
           compilerOptions: {
             sourceMap: true,
             declaration: true,
+            declarationDir: paths.appDist,
             jsx: 'react',
           },
         },
@@ -165,9 +166,8 @@ export async function createRollupConfig(
           },
         },
         check: !opts.transpileOnly,
-        useTsconfigDeclarationDir: Boolean(
-          tsconfigJSON?.compilerOptions?.declarationDir
-        ),
+        // declarationDir is used internally above as a default
+        useTsconfigDeclarationDir: true,
       }),
       babelPluginTsdx({
         exclude: 'node_modules/**',

test/fixtures/build-default/tsconfig.json

@@ -3,6 +3,7 @@
     "module": "ESNext",
     "lib": ["dom", "esnext"],
     "declaration": true,
+    "declarationMap": true,
     "sourceMap": true,
     "rootDir": "./src",
     "strict": true,

test/tests/tsdx-build.test.js

@@ -3,6 +3,8 @@
  */
 
 const shell = require('shelljs');
+const fs = require('fs-extra');
+
 const util = require('../fixtures/util');
 
 shell.config.silent = false;
@@ -42,6 +44,17 @@ describe('tsdx build', () => {
     expect(lib.foo()).toBe('bar');
   });
 
+  it('should create declarationMap files (*.d.ts.map) correctly', async () => {
+    util.setupStageWithFixture(stageName, 'build-default');
+
+    shell.exec('node ../dist/index.js build');
+
+    expect(shell.test('-f', 'dist/index.d.ts.map')).toBeTruthy();
+
+    const dtsmap = await fs.readJSON('dist/index.d.ts.map');
+    expect(dtsmap.sources[0]).toBe('../src/index.ts');
+  });
+
   it('should clean the dist directory before rebuilding', () => {
     util.setupStageWithFixture(stageName, 'build-default');
 
@@ -102,7 +115,7 @@ describe('tsdx build', () => {
     expect(code).toBe(0);
   });
 
-  it('should use the declarationDir when set in tsconfig', () => {
+  it('should use the declarationDir when set in tsconfig', async () => {
     util.setupStageWithFixture(stageName, 'build-withTsconfig');
 
     const output = shell.exec('node ../dist/index.js build --format esm,cjs');
@@ -120,6 +133,9 @@ describe('tsdx build', () => {
     expect(shell.test('-f', 'typings/index.d.ts')).toBeTruthy();
     expect(shell.test('-f', 'typings/index.d.ts.map')).toBeTruthy();
 
+    const dtsmap = await fs.readJSON('typings/index.d.ts.map');
+    expect(dtsmap.sources[0]).toBe('../src/index.ts');
+
     expect(output.code).toBe(0);
   });