util: show all nested proxies when inspecting

Author: BridgeAR

lib/internal/util/inspect.js

@@ -1119,6 +1119,7 @@ function formatValue(ctx, value, recurseTimes, typedArray) {
 
   // Memorize the context for custom inspection on proxies.
   const context = value;
+  let proxies = 0;
   // Always check for proxies to prevent side effects and to prevent triggering
   // any proxy handlers.
   let proxy = getProxyDetails(value, !!ctx.showProxy);
@@ -1135,6 +1136,7 @@ function formatValue(ctx, value, recurseTimes, typedArray) {
       }
       value = proxy;
       proxy = getProxyDetails(value, false);
+      proxies += 1;
     } while (proxy !== undefined);
   }
 
@@ -1151,7 +1153,7 @@ function formatValue(ctx, value, recurseTimes, typedArray) {
       // a counter internally.
       const depth = ctx.depth === null ? null : ctx.depth - recurseTimes;
       const isCrossContext =
-        context !== value || !FunctionPrototypeSymbolHasInstance(Object, context);
+        proxies !== 0 || !FunctionPrototypeSymbolHasInstance(Object, context);
       const ret = FunctionPrototypeCall(
         maybeCustom,
         context,
@@ -1187,10 +1189,13 @@ function formatValue(ctx, value, recurseTimes, typedArray) {
     return ctx.stylize(`[Circular *${index}]`, 'special');
   }
 
-  const formatted = formatRaw(ctx, value, recurseTimes, typedArray);
+  let formatted = formatRaw(ctx, value, recurseTimes, typedArray);
 
-  if (proxy !== undefined) {
-    return `${ctx.stylize('Proxy(', 'special')}${formatted}${ctx.stylize(')', 'special')}`;
+  if (proxies !== 0) {
+    for (let i = 0; i < proxies; i++) {
+      formatted = `${ctx.stylize('Proxy(', 'special')}${formatted}${ctx.stylize(')', 'special')}`;
+    }
+    return formatted;
   }
 
   return formatted;

test/parallel/test-util-inspect-proxy.js

@@ -139,6 +139,10 @@ const expected6 = 'Proxy [\n' +
                   '    Proxy [ Proxy [Array], Proxy [Array] ]\n' +
                   '  ]\n' +
                   ']';
+const expected2NoShowProxy = 'Proxy(Proxy({}))';
+const expected3NoShowProxy = 'Proxy(Proxy(Proxy({})))';
+const expected4NoShowProxy = 'Proxy(Proxy(Proxy(Proxy({}))))';
+const expected5NoShowProxy = 'Proxy(Proxy(Proxy(Proxy(Proxy({})))))';
 assert.strictEqual(
   util.inspect(proxy1, { showProxy: 1, depth: null }),
   expected1);
@@ -148,11 +152,11 @@ assert.strictEqual(util.inspect(proxy4, opts), expected4);
 assert.strictEqual(util.inspect(proxy5, opts), expected5);
 assert.strictEqual(util.inspect(proxy6, opts), expected6);
 assert.strictEqual(util.inspect(proxy1), expected0);
-assert.strictEqual(util.inspect(proxy2), expected0);
-assert.strictEqual(util.inspect(proxy3), expected0);
-assert.strictEqual(util.inspect(proxy4), expected0);
-assert.strictEqual(util.inspect(proxy5), expected0);
-assert.strictEqual(util.inspect(proxy6), expected0);
+assert.strictEqual(util.inspect(proxy2), expected2NoShowProxy);
+assert.strictEqual(util.inspect(proxy3), expected3NoShowProxy);
+assert.strictEqual(util.inspect(proxy4), expected2NoShowProxy);
+assert.strictEqual(util.inspect(proxy5), expected4NoShowProxy);
+assert.strictEqual(util.inspect(proxy6), expected5NoShowProxy);
 
 // Just for fun, let's create a Proxy using Arrays.
 const proxy7 = new Proxy([], []);
@@ -197,8 +201,8 @@ assert.strictEqual(util.format('%s', proxy12), 'Proxy([ 1, 2, 3 ])');
   // Nested proxies should not trigger any proxy handlers.
   const nestedProxy = new Proxy(new Proxy(new Proxy({}, handler), {}), {});
 
-  util.inspect(nestedProxy, { showProxy: true });
-  util.inspect(nestedProxy, { showProxy: false });
+  assert.strictEqual(util.inspect(nestedProxy, { showProxy: true }), 'Proxy [ Proxy [ Proxy [ {}, [Object] ], {} ], {} ]');
+  assert.strictEqual(util.inspect(nestedProxy, { showProxy: false }), expected3NoShowProxy);
 }
 
 {