feat(statement merging): add support for merging type- and lib refere…

…nce directives

src/service/transformer/declaration-bundler/statement-merger/statement-merger.ts

@@ -1,8 +1,11 @@
 import {createExportDeclaration, createNamedExports, SourceFile, TransformerFactory, updateSourceFileNode} from "typescript";
+
 import {DeclarationBundlerOptions} from "../declaration-bundler-options";
 import {normalize} from "path";
 import {mergeExports} from "../util/merge-exports/merge-exports";
 import {mergeImports} from "../util/merge-imports/merge-imports";
+import {mergeTypeReferenceDirectives} from "../util/merge-file-references/merge-type-reference-directives";
+import {mergeLibReferenceDirectives} from "../util/merge-file-references/merge-lib-reference-directives";
 
 export function statementMerger({declarationFilename, ...options}: DeclarationBundlerOptions): TransformerFactory<SourceFile> {
 	return _ => {
@@ -27,9 +30,9 @@ export function statementMerger({declarationFilename, ...options}: DeclarationBu
 					: mergedStatements,
 				sourceFile.isDeclarationFile,
 				sourceFile.referencedFiles,
-				sourceFile.typeReferenceDirectives,
+				mergeTypeReferenceDirectives(sourceFile),
 				sourceFile.hasNoDefaultLib,
-				sourceFile.libReferenceDirectives
+				mergeLibReferenceDirectives(sourceFile)
 			);
 
 			if (options.pluginOptions.debug) {

src/service/transformer/declaration-bundler/util/merge-file-references/merge-lib-reference-directives.ts

@@ -0,0 +1,23 @@
+import {FileReference, SourceFile} from "typescript";
+
+function formatLibReferenceDirective(libName: string): string {
+	return `/// <reference lib="${libName}" />`;
+}
+
+/**
+ * Merges the lib file references of the SourceFile
+ * @param {SourceFile} sourceFile
+ * @return {FileReference[]}
+ */
+export function mergeLibReferenceDirectives(sourceFile: SourceFile): FileReference[] {
+	return (
+		[...new Set<string>(sourceFile.libReferenceDirectives.map(({fileName}) => fileName))]
+			// Don't include those that are already part of the SourceFile
+			.filter(fileName => !sourceFile.text.includes(formatLibReferenceDirective(fileName)))
+			.map(fileName => ({
+				fileName,
+				pos: -1,
+				end: -1
+			}))
+	);
+}

src/service/transformer/declaration-bundler/util/merge-file-references/merge-type-reference-directives.ts

@@ -0,0 +1,23 @@
+import {FileReference, SourceFile} from "typescript";
+
+function formatTypeReferenceDirective(fileName: string): string {
+	return `/// <reference types="${fileName}" />`;
+}
+
+/**
+ * Merges the type file references of the SourceFile
+ * @param {SourceFile} sourceFile
+ * @return {FileReference[]}
+ */
+export function mergeTypeReferenceDirectives(sourceFile: SourceFile): FileReference[] {
+	return (
+		[...new Set<string>(sourceFile.typeReferenceDirectives.map(({fileName}) => fileName))]
+			// Don't include those that are already part of the SourceFile
+			.filter(fileName => !sourceFile.text.includes(formatTypeReferenceDirective(fileName)))
+			.map(fileName => ({
+				fileName,
+				pos: -1,
+				end: -1
+			}))
+	);
+}

test/statement-merge.test.ts

@@ -0,0 +1,30 @@
+import test from "ava";
+import {formatCode} from "./util/format-code";
+import {generateRollupBundle} from "./setup/setup-rollup";
+// tslint:disable:no-duplicate-string
+
+test("Merges identical statements correctly. #1", async t => {
+	const bundle = await generateRollupBundle(
+		[
+			{
+				entry: true,
+				fileName: "index.ts",
+				text: `\
+					export function foo (_arg: Buffer): void {}
+					`
+			}
+		],
+		{debug: true}
+	);
+	const {
+		declarations: [file]
+	} = bundle;
+	t.deepEqual(
+		formatCode(file.code),
+		formatCode(`\
+		/// <reference types="node" />
+		declare function foo(_arg: Buffer): void;
+		export { foo };
+		`)
+	);
+});