process: delay throwing an error using throwDeprecation

This makes sure all warnings that were triggered before a deprecation warning during the same tick are properly handled and logged. It also guarantees that users can not catch the error anymore. Fixes: #17871 PR-URL: #32312 Reviewed-By: Benjamin Gruenbaum <[email protected]> Reviewed-By: Matteo Collina <[email protected]> Reviewed-By: Michaël Zasso <[email protected]>
nodejs · May 23, 2020 · 49745cd · 49745cd
1 parent 5d06a37
commit 49745cd
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Showing 2 changed files with 15 additions and 5 deletions.
diff --git a/lib/internal/process/warning.js b/lib/internal/process/warning.js
@@ -126,8 +126,13 @@ function emitWarning(warning, type, code, ctor) {
   if (warning.name === 'DeprecationWarning') {
     if (process.noDeprecation)
       return;
-    if (process.throwDeprecation)
-      throw warning;
+    if (process.throwDeprecation) {
+      // Delay throwing the error to guarantee that all former warnings were
+      // properly logged.
+      return process.nextTick(() => {
+        throw warning;
+      });
+    }
   }
   process.nextTick(doEmitWarning, warning);
 }

diff --git a/test/parallel/test-process-warning.js b/test/parallel/test-process-warning.js
@@ -38,9 +38,14 @@ function test4() {
   // process.emitWarning will throw when process.throwDeprecation is true
   // and type is `DeprecationWarning`.
   process.throwDeprecation = true;
-  assert.throws(
-    () => process.emitWarning('test', 'DeprecationWarning'),
-    /^DeprecationWarning: test$/);
+  process.once('uncaughtException', (err) => {
+    assert.match(err.toString(), /^DeprecationWarning: test$/);
+  });
+  try {
+    process.emitWarning('test', 'DeprecationWarning');
+  } catch {
+    assert.fail('Unreachable');
+  }
   process.throwDeprecation = false;
   setImmediate(test5);
 }