test: add deprecation code to expectWarning

This commit adds a deprecation code to expectWarning and updates the
function to check the passed code against the code property on the
warning object.

Not all warnings have a deprecation code so for those that don't an
explicit code of common.noWarnCode is required. Passing this skips the
assertion of the code.

PR-URL: https://github.com/nodejs/node/pull/19474
Reviewed-By: Michaël Zasso <targos@protonmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Tobias Nießen <tniessen@tnie.de>

2 files changed, 37 insertions, 12 deletions

diff --git a/test/common/README.md b/test/common/README.md
index 24468bdfd7..765ebe0123 100644
--- a/test/common/README.md
+++ b/test/common/README.md
@@ -108,11 +108,17 @@ Indicates if there is more than 1gb of total memory.
   returned function has not been called exactly `exact` number of times when the
   test is complete, then the test will fail.
 
-### expectWarning(name, expected)
+### expectWarning(name, expected, code)
 * `name` [<string>]
 * `expected` [<string>] | [<Array>]
+* `code` [<string>]
 
-Tests whether `name` and `expected` are part of a raised warning.
+Tests whether `name`, `expected`, and `code` are part of a raised warning. If
+an expected warning does not have a code then `common.noWarnCode` can be used
+to indicate this.
+
+### noWarnCode
+See `common.expectWarning()` for usage.
 
 ### fileExists(pathname)
 * pathname [<string>]
diff --git a/test/common/index.js b/test/common/index.js
index ff1dc0ce26..f13e61df8c 100644
--- a/test/common/index.js
+++ b/test/common/index.js
@@ -611,20 +611,32 @@ exports.isAlive = function isAlive(pid) {
   }
 };
 
-function expectWarning(name, expectedMessages) {
+exports.noWarnCode = 'no_expected_warning_code';
+
+function expectWarning(name, expected) {
+  const map = new Map(expected);
   return exports.mustCall((warning) => {
     assert.strictEqual(warning.name, name);
-    assert.ok(expectedMessages.includes(warning.message),
+    assert.ok(map.has(warning.message),
               `unexpected error message: "${warning.message}"`);
+    const code = map.get(warning.message);
+    if (code === undefined) {
+      throw new Error('An error code must be specified or use ' +
+      'common.noWarnCode if there is no error code. The error  ' +
+      `code for this warning was ${warning.code}`);
+    }
+    if (code !== exports.noWarnCode) {
+      assert.strictEqual(warning.code, code);
+    }
     // Remove a warning message after it is seen so that we guarantee that we
     // get each message only once.
-    expectedMessages.splice(expectedMessages.indexOf(warning.message), 1);
-  }, expectedMessages.length);
+    map.delete(expected);
+  }, map.size);
 }
 
-function expectWarningByName(name, expected) {
+function expectWarningByName(name, expected, code) {
   if (typeof expected === 'string') {
-    expected = [expected];
+    expected = [[expected, code]];
   }
   process.on('warning', expectWarning(name, expected));
 }
@@ -633,8 +645,15 @@ function expectWarningByMap(warningMap) {
   const catchWarning = {};
   Object.keys(warningMap).forEach((name) => {
     let expected = warningMap[name];
-    if (typeof expected === 'string') {
-      expected = [expected];
+    if (!Array.isArray(expected)) {
+      throw new Error('warningMap entries must be arrays consisting of two ' +
+      'entries: [message, warningCode]');
+    }
+    if (!(Array.isArray(expected[0]))) {
+      if (expected.length === 0) {
+        return;
+      }
+      expected = [[expected[0], expected[1]]];
     }
     catchWarning[name] = expectWarning(name, expected);
   });
@@ -644,9 +663,9 @@ function expectWarningByMap(warningMap) {
 // accepts a warning name and description or array of descriptions or a map
 // of warning names to description(s)
 // ensures a warning is generated for each name/description pair
-exports.expectWarning = function(nameOrMap, expected) {
+exports.expectWarning = function(nameOrMap, expected, code) {
   if (typeof nameOrMap === 'string') {
-    expectWarningByName(nameOrMap, expected);
+    expectWarningByName(nameOrMap, expected, code);
   } else {
     expectWarningByMap(nameOrMap);
   }