3 files changed, 29 insertions, 11 deletions
diff --git a/js/os.ts b/js/os.ts
index 551cb1ea6..11407cfb0 100644
--- a/js/os.ts
+++ b/js/os.ts
@@ -13,16 +13,10 @@ export let pid: number;
 /** Reflects the NO_COLOR environment variable: https://no-color.org/ */
 export let noColor: boolean;
 
-/** Path to the current deno process's executable file.
- * Requires the `--allow-env` flag, otherwise it'll be set to an empty `string`.
- */
-export let execPath: string;
-
-function setGlobals(pid_: number, noColor_: boolean, execPath_: string): void {
+function setGlobals(pid_: number, noColor_: boolean): void {
   assert(!pid);
   pid = pid_;
   noColor = noColor_;
-  execPath = execPath_;
 }
 
 /** Check if running in terminal.
@@ -127,7 +121,7 @@ export function start(
 
   util.setLogDebug(startResMsg.debugFlag(), source);
 
-  setGlobals(startResMsg.pid(), startResMsg.noColor(), startResMsg.execPath()!);
+  setGlobals(startResMsg.pid(), startResMsg.noColor());
 
   if (preserveDenoNamespace) {
     util.immutableDefine(window, "Deno", window.Deno);
@@ -164,3 +158,19 @@ export function homeDir(): string {
 
   return path;
 }
+
+export function execPath(): string {
+  const builder = flatbuffers.createBuilder();
+  const inner = msg.ExecPath.createExecPath(builder);
+  const baseRes = sendSync(builder, msg.Any.ExecPath, inner)!;
+  assert(msg.Any.ExecPathRes === baseRes.innerType());
+  const res = new msg.ExecPathRes();
+  assert(baseRes.inner(res) != null);
+  const path = res.path();
+
+  if (!path) {
+    throw new Error("Could not get home directory.");
+  }
+
+  return path;
+}
diff --git a/js/os_test.ts b/js/os_test.ts
index b2f511b5e..28c8b6a0b 100644
--- a/js/os_test.ts
+++ b/js/os_test.ts
@@ -56,9 +56,17 @@ testPerm({ env: false }, function homeDirPerm(): void {
 });
 
 testPerm({ env: true }, function execPath(): void {
-  assertNotEquals(Deno.execPath, "");
+  assertNotEquals(Deno.execPath(), "");
 });
 
 testPerm({ env: false }, function execPathPerm(): void {
-  assertEquals(Deno.execPath, "");
+  let caughtError = false;
+  try {
+    Deno.execPath();
+  } catch (err) {
+    caughtError = true;
+    assertEquals(err.kind, Deno.ErrorKind.PermissionDenied);
+    assertEquals(err.name, "PermissionDenied");
+  }
+  assert(caughtError);
 });
diff --git a/js/unit_test_runner.ts b/js/unit_test_runner.ts
index 55ccd14bf..24dae7706 100755
--- a/js/unit_test_runner.ts
+++ b/js/unit_test_runner.ts
@@ -53,7 +53,7 @@ async function main(): Promise<void> {
     const cliPerms = permsToCliFlags(perms);
     // run subsequent tests using same deno executable
     const args = [
-      Deno.execPath,
+      Deno.execPath(),
       "run",
       "--no-prompt",
       ...cliPerms,