feat(*): impl declaration option basic support

src/helpers.ts

@@ -18,9 +18,15 @@ function isSourceMapEmit(fileName, outputFileName, sourceFileName) {
         && (outputFileName.substr(-7) === '.js.map' || outputFileName.substr(-8) === '.jsx.map');
 }
 
+function isDeclarationEmit(fileName, outputFileName, sourceFileName) {
+    return sourceFileName === fileName
+        && (outputFileName.substr(-5) === '.d.ts');
+}
+
 export function findResultFor(output: host.IEmitOutput, fileName: string) {
     let text;
     let sourceMap;
+    let declaration: host.IOutputFile;
     fileName = withoutExt(path.normalize(fileName));
 
     for (let i = 0; i < output.outputFiles.length; i++) {
@@ -33,10 +39,14 @@ export function findResultFor(output: host.IEmitOutput, fileName: string) {
         if (isSourceMapEmit(fileName, outputFileName, sourceFileName)) {
             sourceMap = o.text;
         }
+        if (isDeclarationEmit(fileName, outputFileName, sourceFileName)) {
+            declaration = o;
+        }
     }
     return {
         text: text,
-        sourceMap: sourceMap
+        sourceMap: sourceMap,
+        declaration
     };
 }
 

src/index.ts

@@ -119,6 +119,13 @@ async function compiler(webpack: IWebPack, text: string): Promise<void> {
                     throw new Error('No output found for ' + fileName);
                 }
 
+                if (result.declaration) {
+                    webpack.emitFile(
+                        path.relative(process.cwd(), result.declaration.sourceName),
+                        result.declaration.text
+                    );
+                }
+
                 resultText = result.text;
 
                 let sourceFileName = fileName.replace(process.cwd() + '/', '');

src/instance.ts

@@ -57,6 +57,7 @@ export interface IWebPack {
     resolve: () => void;
     addDependency: (dep: string) => void;
     clearDependencies: () => void;
+    emitFile: (fileName: string, text: string) => void;
     options: {
         atl?: {
             plugins: LoaderPluginDef[]
@@ -358,6 +359,21 @@ function setupAfterCompile(compiler, instanceName, forkChecker = false) {
             }
         });
 
+        if (instance.options.declaration) {
+            phantomImports.forEach(imp => {
+                let output = instance.tsState.services.getEmitOutput(imp);
+                let declarationFile = output.outputFiles.filter(filePath =>
+                    !!filePath.name.match(/\.d.ts$/))[0];
+                if (declarationFile) {
+                    let assetPath = path.relative(process.cwd(), declarationFile.name);
+                    compilation.assets[assetPath] = {
+                        source: () => declarationFile.text,
+                        size: () => declarationFile.text.length
+                    };
+                }
+            });
+        }
+
         instance.compiledFiles = {};
         compilation.fileDependencies.push.apply(compilation.fileDependencies, phantomImports);
         compilation.fileDependencies = _.uniq(compilation.fileDependencies);

src/test/declaration.ts

@@ -0,0 +1,29 @@
+import {
+    cleanAndCompile, expect, readOutputFile,
+    fixturePath, readFixture, expectSource, createConfig
+} from './utils';
+
+describe('main test', function() {
+
+    it('should emit declaration files', async function() {
+        // babel need some time to init
+        this.timeout(10000);
+
+        let config =  {
+            entry: fixturePath(['declaration', 'basic.ts'])
+        };
+
+        let loaderQuery = {
+            declaration: true
+        };
+
+        let stats = await cleanAndCompile(createConfig(config, { loaderQuery }));
+        expect(stats.compilation.errors.length).eq(0);
+        let assets = Object.keys(stats.compilation.assets);
+
+        expect(assets).to.include('src/test/fixtures/declaration/basic.d.ts');
+
+        // elided import
+        expect(assets).to.include('src/test/fixtures/declaration/iface.d.ts');
+    });
+});

src/test/fixtures/declaration/basic.ts

@@ -0,0 +1,3 @@
+import { Iface } from './iface';
+
+export function foo(iface: Iface): Iface { return iface; }

src/test/fixtures/declaration/iface.ts

@@ -0,0 +1,4 @@
+
+export interface Iface {
+    name: string;
+}

src/tsconfig.json

@@ -27,12 +27,17 @@
         "./resolver.ts",
         "./test/babel.ts",
         "./test/checker.ts",
+        "./test/declaration.ts",
         "./test/fixtures/babel/babel.ts",
         "./test/fixtures/basic/basic.ts",
         "./test/fixtures/checker/to-check.ts",
+        "./test/fixtures/declaration/basic.ts",
+        "./test/fixtures/declaration/iface.ts",
         "./test/fixtures/errors/with-type-errors.ts",
         "./test/fixtures/salsa/index.ts",
         "./test/index.ts",
+        "./test/output/src/test/fixtures/declaration/basic.d.ts",
+        "./test/output/src/test/fixtures/declaration/iface.d.ts",
         "./test/salsa.ts",
         "./test/utils.ts",
         "./tsconfig-utils.ts"