Improve script/category name validation

- Use better error messages with more context.
- Unify their validation logic and share tests.
- Validate also type of the name.
- Refactor node (Script/Category) parser tests for easier future
  changes and cleaner test code (using `TestBuilder` to do dirty work in
  unified way).
- Add more tests. Custom `Error` properties are compared manually due to
  `chai` not supporting deep equality checks (chaijs/chai#1065,
  chaijs/chai#1405).

tests/unit/shared/Assertions/ExpectThrowsError.ts

@@ -0,0 +1,50 @@
+// import * as assert from 'assert';
+import { expect } from 'chai';
+
+// Using manual checks because expect(act).to.throw(obj) does not work
+// chaijs/chai#1065, chaijs/chai#1405
+export function expectThrowsError<T extends Error>(delegate: () => void, expected: T) {
+  // arrange
+  if (!expected) {
+    throw new Error('missing expected');
+  }
+  let actual: T | undefined;
+  // act
+  try {
+    delegate();
+  } catch (error) {
+    actual = error;
+  }
+  // assert
+  expect(Boolean(actual)).to.equal(true, `Expected to throw "${expected.name}" but delegate did not throw at all.`);
+  expect(Boolean(actual?.stack)).to.equal(true, 'Empty stack trace.');
+  expect(expected.message).to.equal(actual.message);
+  expect(expected.name).to.equal(actual.name);
+  expectDeepEqualsIgnoringUndefined(expected, actual);
+}
+
+function expectDeepEqualsIgnoringUndefined(expected: unknown, actual: unknown) {
+  const actualClean = removeUndefinedProperties(actual);
+  const expectedClean = removeUndefinedProperties(expected);
+  expect(expectedClean).to.deep.equal(actualClean);
+}
+
+function removeUndefinedProperties(obj: unknown): unknown {
+  return Object.keys(obj ?? {})
+    .reduce((acc, key) => {
+      const value = obj[key];
+      switch (typeof value) {
+        case 'object': {
+          const cleanValue = removeUndefinedProperties(value); // recurse
+          if (!Object.keys(cleanValue).length) {
+            return { ...acc };
+          }
+          return { ...acc, [key]: cleanValue };
+        }
+        case 'undefined':
+          return { ...acc };
+        default:
+          return { ...acc, [key]: value };
+      }
+    }, {});
+}