4 files changed, 46 insertions, 9 deletions

diff --git a/cli/rt/01_web_util.js b/cli/rt/01_web_util.js
index 1b7f7b83a..ee8992eb2 100644
--- a/cli/rt/01_web_util.js
+++ b/cli/rt/01_web_util.js
@@ -1,6 +1,8 @@
 // Copyright 2018-2020 the Deno authors. All rights reserved. MIT license.
 
 ((window) => {
+  const illegalConstructorKey = Symbol("illegalConstructorKey");
+
   function isInvalidDate(x) {
     return isNaN(x.getTime());
   }
@@ -146,6 +148,7 @@
   }
 
   window.__bootstrap.webUtil = {
+    illegalConstructorKey,
     isInvalidDate,
     requiredArguments,
     immutableDefine,
diff --git a/cli/rt/40_performance.js b/cli/rt/40_performance.js
index a785d23b1..b921ca43a 100644
--- a/cli/rt/40_performance.js
+++ b/cli/rt/40_performance.js
@@ -2,7 +2,7 @@
 
 ((window) => {
   const { opNow } = window.__bootstrap.timers;
-  const { cloneValue } = window.__bootstrap.webUtil;
+  const { cloneValue, illegalConstructorKey } = window.__bootstrap.webUtil;
 
   const customInspect = Symbol.for("Deno.customInspect");
   let performanceEntries = [];
@@ -74,7 +74,11 @@
       entryType,
       startTime,
       duration,
+      key,
     ) {
+      if (key != illegalConstructorKey) {
+        throw new TypeError("Illegal constructor.");
+      }
       this.#name = name;
       this.#entryType = entryType;
       this.#startTime = startTime;
@@ -110,7 +114,7 @@
       name,
       { detail = null, startTime = now() } = {},
     ) {
-      super(name, "mark", startTime, 0);
+      super(name, "mark", startTime, 0, illegalConstructorKey);
       if (startTime < 0) {
         throw new TypeError("startTime cannot be negative");
       }
@@ -152,8 +156,12 @@
       startTime,
       duration,
       detail = null,
+      key,
     ) {
-      super(name, "measure", startTime, duration);
+      if (key != illegalConstructorKey) {
+        throw new TypeError("Illegal constructor.");
+      }
+      super(name, "measure", startTime, duration, illegalConstructorKey);
       this.#detail = cloneValue(detail);
     }
 
@@ -177,6 +185,12 @@
   }
 
   class Performance {
+    constructor(key) {
+      if (key != illegalConstructorKey) {
+        throw new TypeError("Illegal constructor.");
+      }
+    }
+
     clearMarks(markName) {
       if (markName == null) {
         performanceEntries = performanceEntries.filter(
@@ -302,6 +316,7 @@
         typeof startOrMeasureOptions === "object"
           ? startOrMeasureOptions.detail ?? null
           : null,
+        illegalConstructorKey,
       );
       performanceEntries.push(entry);
       return entry;
@@ -312,10 +327,13 @@
     }
   }
 
+  const performance = new Performance(illegalConstructorKey);
+
   window.__bootstrap.performance = {
     PerformanceEntry,
     PerformanceMark,
     PerformanceMeasure,
     Performance,
+    performance,
   };
 })(this);
diff --git a/cli/rt/40_permissions.js b/cli/rt/40_permissions.js
index 983d0895a..982e4c842 100644
--- a/cli/rt/40_permissions.js
+++ b/cli/rt/40_permissions.js
@@ -2,6 +2,7 @@
 
 ((window) => {
   const core = window.Deno.core;
+  const { illegalConstructorKey } = window.__bootstrap.webUtil;
 
   function opQuery(desc) {
     return core.jsonOpSync("op_query_permission", desc).state;
@@ -16,30 +17,45 @@
   }
 
   class PermissionStatus {
-    constructor(state) {
+    constructor(state, key) {
+      if (key != illegalConstructorKey) {
+        throw new TypeError("Illegal constructor.");
+      }
       this.state = state;
     }
     // TODO(kt3k): implement onchange handler
   }
 
   class Permissions {
+    constructor(key) {
+      if (key != illegalConstructorKey) {
+        throw new TypeError("Illegal constructor.");
+      }
+    }
+
     query(desc) {
       const state = opQuery(desc);
-      return Promise.resolve(new PermissionStatus(state));
+      return Promise.resolve(
+        new PermissionStatus(state, illegalConstructorKey),
+      );
     }
 
     revoke(desc) {
       const state = opRevoke(desc);
-      return Promise.resolve(new PermissionStatus(state));
+      return Promise.resolve(
+        new PermissionStatus(state, illegalConstructorKey),
+      );
     }
 
     request(desc) {
       const state = opRequest(desc);
-      return Promise.resolve(new PermissionStatus(state));
+      return Promise.resolve(
+        new PermissionStatus(state, illegalConstructorKey),
+      );
     }
   }
 
-  const permissions = new Permissions();
+  const permissions = new Permissions(illegalConstructorKey);
 
   window.__bootstrap.permissions = {
     permissions,
diff --git a/cli/rt/99_main.js b/cli/rt/99_main.js
index a15de081c..40ea8434b 100644
--- a/cli/rt/99_main.js
+++ b/cli/rt/99_main.js
@@ -235,7 +235,7 @@ delete Object.prototype.__proto__;
     crypto: util.readOnly(crypto),
     dispatchEvent: util.readOnly(EventTarget.prototype.dispatchEvent),
     fetch: util.writable(fetch.fetch),
-    performance: util.writable(new performance.Performance()),
+    performance: util.writable(performance.performance),
     removeEventListener: util.readOnly(
       EventTarget.prototype.removeEventListener,
     ),