2 files changed, 17 insertions, 3 deletions
diff --git a/cli/js/compiler/bootstrap.ts b/cli/js/compiler/bootstrap.ts
index 63de783cf..5f9dfad92 100644
--- a/cli/js/compiler/bootstrap.ts
+++ b/cli/js/compiler/bootstrap.ts
@@ -20,6 +20,7 @@ ts.libMap.set("deno.ns", "lib.deno.ns.d.ts");
 ts.libMap.set("deno.window", "lib.deno.window.d.ts");
 ts.libMap.set("deno.worker", "lib.deno.worker.d.ts");
 ts.libMap.set("deno.shared_globals", "lib.deno.shared_globals.d.ts");
+ts.libMap.set("deno.unstable", "lib.deno.unstable.d.ts");
 
 // this pre-populates the cache at snapshot time of our library files, so they
 // are available in the future when needed.
@@ -30,6 +31,7 @@ host.getSourceFile(
   `${ASSETS}/lib.deno.shared_globals.d.ts`,
   ts.ScriptTarget.ESNext
 );
+host.getSourceFile(`${ASSETS}/lib.deno.unstable.d.ts`, ts.ScriptTarget.ESNext);
 
 export const TS_SNAPSHOT_PROGRAM = ts.createProgram({
   rootNames: [`${ASSETS}/bootstrap.ts`],
diff --git a/cli/js/compiler/host.ts b/cli/js/compiler/host.ts
index 70e712ffe..afe184d3e 100644
--- a/cli/js/compiler/host.ts
+++ b/cli/js/compiler/host.ts
@@ -14,9 +14,8 @@ export enum CompilerHostTarget {
 
 export interface CompilerHostOptions {
   bundle?: boolean;
-
   target: CompilerHostTarget;
-
+  unstable?: boolean;
   writeFile: WriteFileCallback;
 }
 
@@ -146,13 +145,26 @@ export class Host implements ts.CompilerHost {
 
   /* Deno specific APIs */
 
-  constructor({ bundle = false, target, writeFile }: CompilerHostOptions) {
+  constructor({
+    bundle = false,
+    target,
+    unstable,
+    writeFile,
+  }: CompilerHostOptions) {
     this.#target = target;
     this.#writeFile = writeFile;
     if (bundle) {
       // options we need to change when we are generating a bundle
       Object.assign(this.#options, defaultBundlerOptions);
     }
+    if (unstable) {
+      this.#options.lib = [
+        target === CompilerHostTarget.Worker
+          ? "lib.deno.worker.d.ts"
+          : "lib.deno.window.d.ts",
+        "lib.deno.unstable.d.ts",
+      ];
+    }
   }
 
   configure(path: string, configurationText: string): ConfigureResponse {