fixup! process: runtime deprecate changing process.config

nodejs · jasnell · Jan 12, 2021 · Jan 13, 2021 · Jan 14, 2021 · Jan 13, 2021
commit 80bf075a38660c89bf500dd32be22e95d5412379
diff --git a/doc/api/process.md b/doc/api/process.md
@@ -759,6 +759,10 @@ This feature is not available in [`Worker`][] threads.
 ## `process.config`
 <!-- YAML
 added: v0.7.7
+changes:
+  - version: REPLACEME
+    pr-url: https://github.com/nodejs/node/pull/36902
+    description: Modifying process.config has been deprecated.
 -->
 
 * {Object}
@@ -803,6 +807,10 @@ The `process.config` property is **not** read-only and there are existing
 modules in the ecosystem that are known to extend, modify, or entirely replace
 the value of `process.config`.
 
+Modifying the `process.config` property, or any child-property of the
+`process.config` object has been deprecated. The `process.config` will be made
+read-only in a future release.
+
 ## `process.connected`
 <!-- YAML
 added: v0.7.2

diff --git a/lib/internal/bootstrap/node.js b/lib/internal/bootstrap/node.js
@@ -43,7 +43,10 @@ const {
   JSONParse,
   ObjectDefineProperty,
   ObjectGetPrototypeOf,
+  ObjectPreventExtensions,
   ObjectSetPrototypeOf,
+  ReflectGet,
+  ReflectSet,
   SymbolToStringTag,
 } = primordials;
 const config = internalBinding('config');
@@ -61,19 +64,70 @@ process._exiting = false;
 const nativeModule = internalBinding('native_module');
 
 // TODO(@jasnell): Once this has gone through one full major
-// release cycle, remove the setter and update the getter to
-// either return a read-only object or always return a freshly
-// parsed version of nativeModule.config.
-let processConfig = JSONParse(nativeModule.config);
+// release cycle, remove the Proxy and setter and update the
+// getter to either return a read-only object or always return
+// a freshly parsed version of nativeModule.config.
+
+const deprecationHandler = {
+  warned: false,
+  message: 'Setting process.config is deprecated. ' +
+           'In the future the property will be read-only.',
+  code: 'DEP0XXX',
+  maybeWarn() {
+    if (!this.warned) {
+      process.emitWarning(this.message, {
+        type: 'DeprecationWarning',
+        code: this.code
+      });
+      this.warned = true;
+    }
+  },
+
+  defineProperty(target, key, descriptor) {
+    this.maybeWarn();
+    return ObjectDefineProperty(target, key, descriptor);
+  },
+
+  deleteProperty(target, key) {
+    this.maybeWarn();
+    delete target[key];
+  },
+
+  preventExtensions(target) {
+    this.maybeWarn();
+    return ObjectPreventExtensions(target);
+  },
+
+  set(target, key, value) {
+    this.maybeWarn();
+    return ReflectSet(target, key, value);
+  },
+
+  get(target, key, receiver) {
+    const val = ReflectGet(target, key, receiver);
+    if (val != null && typeof val === 'object')
+      return new Proxy(val, deprecationHandler);
+    return val;
+  },
+
+  setPrototypeOf(target, proto) {
+    this.maybeWarn();
+    return ObjectSetPrototypeOf(target, proto);
+  }
+};
+
+let processConfig = new Proxy(
+  JSONParse(nativeModule.config),
+  deprecationHandler);
+
 ObjectDefineProperty(process, 'config', {
   enumerable: true,
   configurable: true,
   get() { return processConfig; },
-  set: deprecate(
-    (value) => { processConfig = value; },
-    'Setting process.config is deprecated. ' +
-    'In the future the property will be read-only.',
-    'DEP0XXX')
+  set(value) {
+    deprecationHandler.maybeWarn();
+    processConfig = value;
+  }
 });
 
 require('internal/worker/js_transferable').setup();