test: refactor `common.expectWarning()`

The current API is somewhat confusing at times and simpler usage is
possible. This overloads the arguments further to accept objects
with deprecation codes as property keys. It also adds documentation
for the different possible styles.

Besides that it is now going to validate for the code being present
in case of deprecations but not for other cases. The former validation
was not consistent as it only validated some cases and accepted
undefined instead of `common.noWarnCode`. This check is removed due to
the lack of consistency. `common.noWarnCode` is completely removed
due to just being sugar for `undefined`.

This also verifies that the warning order is identical to the order
in which they are triggered.

PR-URL: https://github.com/nodejs/node/pull/25251
Reviewed-By: Daniel Bevenius <daniel.bevenius@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>

1 files changed, 27 insertions, 39 deletions

diff --git a/test/common/index.js b/test/common/index.js
index 5d9a4b31e3..ea59009ba5 100644
--- a/test/common/index.js
+++ b/test/common/index.js
@@ -497,54 +497,43 @@ function isAlive(pid) {
   }
 }
 
-function _expectWarning(name, expected) {
-  const map = new Map(expected);
+function _expectWarning(name, expected, code) {
+  if (typeof expected === 'string') {
+    expected = [[expected, code]];
+  } else if (!Array.isArray(expected)) {
+    expected = Object.entries(expected).map(([a, b]) => [b, a]);
+  } else if (!(Array.isArray(expected[0]))) {
+    expected = [[expected[0], expected[1]]];
+  }
+  // Deprecation codes are mandatory, everything else is not.
+  if (name === 'DeprecationWarning') {
+    expected.forEach(([_, code]) => assert(code, expected));
+  }
   return mustCall((warning) => {
+    const [ message, code ] = expected.shift();
     assert.strictEqual(warning.name, name);
-    assert.ok(map.has(warning.message),
-              `unexpected error message: "${warning.message}"`);
-    const code = map.get(warning.message);
+    assert.strictEqual(warning.message, message);
     assert.strictEqual(warning.code, code);
-    // Remove a warning message after it is seen so that we guarantee that we
-    // get each message only once.
-    map.delete(expected);
   }, expected.length);
 }
 
-function expectWarningByName(name, expected, code) {
-  if (typeof expected === 'string') {
-    expected = [[expected, code]];
-  }
-  process.on('warning', _expectWarning(name, expected));
-}
+let catchWarning;
 
-function expectWarningByMap(warningMap) {
-  const catchWarning = {};
-  Object.keys(warningMap).forEach((name) => {
-    let expected = warningMap[name];
-    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);
-  });
-  process.on('warning', (warning) => catchWarning[warning.name](warning));
-}
-
-// 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
+// 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.
+// The expected messages have to be unique per `expectWarning()` call.
 function expectWarning(nameOrMap, expected, code) {
+  if (catchWarning === undefined) {
+    catchWarning = {};
+    process.on('warning', (warning) => catchWarning[warning.name](warning));
+  }
   if (typeof nameOrMap === 'string') {
-    expectWarningByName(nameOrMap, expected, code);
+    catchWarning[nameOrMap] = _expectWarning(nameOrMap, expected, code);
   } else {
-    expectWarningByMap(nameOrMap);
+    Object.keys(nameOrMap).forEach((name) => {
+      catchWarning[name] = _expectWarning(name, nameOrMap[name]);
+    });
   }
 }
 
@@ -758,7 +747,6 @@ module.exports = {
   mustCallAtLeast,
   mustNotCall,
   nodeProcessAborted,
-  noWarnCode: undefined,
   PIPE,
   platformTimeout,
   printSkipMessage,