5 files changed, 85 insertions, 1 deletions

diff --git a/tools/ts_library_builder/ast_util.ts b/tools/ts_library_builder/ast_util.ts
index 9bb7e8edc..58aa7fb9c 100644
--- a/tools/ts_library_builder/ast_util.ts
+++ b/tools/ts_library_builder/ast_util.ts
@@ -243,6 +243,32 @@ export function getSourceComment(
   return `\n// @url ${relative(rootPath, sourceFile.getFilePath())}\n\n`;
 }
 
+interface InlineFilesOptions {
+  basePath: string;
+  debug?: boolean;
+  inline: string[];
+  targetSourceFile: SourceFile;
+}
+
+/** Inline files into the target source file. */
+export function inlineFiles({
+  basePath,
+  debug,
+  inline,
+  targetSourceFile
+}: InlineFilesOptions) {
+  for (const filename of inline) {
+    const text = readFileSync(filename, {
+      encoding: "utf8"
+    });
+    targetSourceFile.addStatements(
+      debug
+        ? `\n// @url ${relative(basePath, filename)}\n\n${text}`
+        : `\n${text}`
+    );
+  }
+}
+
 /**
  * Load and write to a virtual file system all the default libs needed to
  * resolve types on project.
diff --git a/tools/ts_library_builder/build_library.ts b/tools/ts_library_builder/build_library.ts
index 286d13d11..93d2da661 100644
--- a/tools/ts_library_builder/build_library.ts
+++ b/tools/ts_library_builder/build_library.ts
@@ -16,6 +16,7 @@ import {
   checkDiagnostics,
   flattenNamespace,
   getSourceComment,
+  inlineFiles,
   loadDtsFiles,
   loadFiles,
   logDiagnostics,
@@ -42,6 +43,11 @@ export interface BuildLibraryOptions {
   debug?: boolean;
 
   /**
+   * An array of files that should be inlined into the library
+   */
+  inline?: string[];
+
+  /**
    * The path to the output library
    */
   outFile: string;
@@ -278,6 +284,7 @@ export function mergeGlobal({
 export function main({
   basePath,
   buildPath,
+  inline,
   debug,
   outFile,
   silent
@@ -288,6 +295,12 @@ export function main({
     console.log();
     console.log(`basePath: "${basePath}"`);
     console.log(`buildPath: "${buildPath}"`);
+    if (inline && inline.length) {
+      console.log(`inline:`);
+      for (const filename of inline) {
+        console.log(`  "${filename}"`);
+      }
+    }
     console.log(`debug: ${!!debug}`);
     console.log(`outFile: "${outFile}"`);
     console.log();
@@ -431,6 +444,17 @@ export function main({
     console.log(`Merged "globals" into global scope.`);
   }
 
+  // Inline any files that were passed in, to be used to add additional libs
+  // which are not part of TypeScript.
+  if (inline && inline.length) {
+    inlineFiles({
+      basePath,
+      debug,
+      inline,
+      targetSourceFile: libDTs
+    });
+  }
+
   // Add the preamble
   libDTs.insertStatements(0, libPreamble);
 
diff --git a/tools/ts_library_builder/main.ts b/tools/ts_library_builder/main.ts
index 8dc6cfabe..c3192a753 100644
--- a/tools/ts_library_builder/main.ts
+++ b/tools/ts_library_builder/main.ts
@@ -7,6 +7,7 @@ import { main as buildRuntimeLib } from "./build_library";
 let basePath = process.cwd();
 let buildPath = path.join(basePath, "out", "debug");
 let outFile = path.join(buildPath, "gen", "lib", "lib.d.ts");
+let inline: string[] = [];
 let debug = false;
 let silent = false;
 
@@ -19,6 +20,11 @@ process.argv.forEach((arg, i, argv) => {
     case "--buildPath":
       buildPath = path.resolve(argv[i + 1]);
       break;
+    case "--inline":
+      inline = argv[i + 1].split(",").map(filename => {
+        return path.resolve(filename);
+      });
+      break;
     case "--outFile":
       outFile = path.resolve(argv[i + 1]);
       break;
@@ -35,6 +41,7 @@ buildRuntimeLib({
   basePath,
   buildPath,
   debug,
+  inline,
   outFile,
   silent
 });
diff --git a/tools/ts_library_builder/test.ts b/tools/ts_library_builder/test.ts
index a60c7cb05..acc2c43db 100644
--- a/tools/ts_library_builder/test.ts
+++ b/tools/ts_library_builder/test.ts
@@ -11,7 +11,7 @@ import {
   test
 } from "../../js/deps/https/deno.land/x/std/testing/mod";
 import { flatten, mergeGlobal } from "./build_library";
-import { loadDtsFiles } from "./ast_util";
+import { inlineFiles, loadDtsFiles } from "./ast_util";
 
 const { ModuleKind, ModuleResolutionKind, ScriptTarget } = ts;
 
@@ -167,6 +167,26 @@ test(function buildLibraryMerge() {
   assertEqual(typeAliases.length, 1);
 });
 
+test(function testInlineFiles() {
+  const {
+    basePath,
+    buildPath,
+    debug,
+    outputSourceFile: targetSourceFile
+  } = setupFixtures();
+
+  inlineFiles({
+    basePath,
+    debug,
+    inline: [`${buildPath}/lib.extra.d.ts`],
+    targetSourceFile
+  });
+
+  assert(targetSourceFile.getNamespace("Qat") != null);
+  const qatNamespace = targetSourceFile.getNamespaceOrThrow("Qat");
+  assert(qatNamespace.getClass("Foo") != null);
+});
+
 // TODO author unit tests for `ast_util.ts`
 
 runTests();
diff --git a/tools/ts_library_builder/testdata/lib.extra.d.ts b/tools/ts_library_builder/testdata/lib.extra.d.ts
new file mode 100644
index 000000000..8dc197334
--- /dev/null
+++ b/tools/ts_library_builder/testdata/lib.extra.d.ts
@@ -0,0 +1,7 @@
+// comment
+
+declare namespace Qat {
+  class Foo {
+    bar: string;
+  }
+}