Test runner: Detect extra property in 'actual' but not in 'expected'. (#407)

* Test runner: Detect extra property in 'actual' but not in 'expected'.

Also update all expected.json where this would result in errors.

* Include rmExpected.js script in case it is needed again

scripts/rmExpected.js

@@ -0,0 +1,24 @@
+// Use this to remove all "expected.json" in all tests.
+
+const { existsSync, readdirSync, statSync, unlinkSync } = require("fs");
+const { join } = require("path");
+
+const rootPath = join(__dirname, "..", "test", "fixtures");
+
+for (const fixtureName of readdirSync(rootPath)) {
+    const fixturePath = join(rootPath, fixtureName);
+    for (const suiteName of readdirSync(fixturePath)) {
+        const suitePath = join(fixturePath, suiteName);
+        if (!statSync(suitePath).isDirectory()) {
+            continue;
+        }
+
+        for (const testName of readdirSync(suitePath)) {
+            const testPath = join(suitePath, testName);
+            const expectedPath = join(testPath, "expected.json");
+            if (existsSync(expectedPath)) {
+                unlinkSync(expectedPath);
+            }
+        }
+    }
+}