Chore: add tests for ruleset create utility

Build/lib/create-file.test.ts

@@ -0,0 +1,53 @@
+import { expect } from 'chai';
+import { fileEqual } from './create-file';
+
+// eslint-disable-next-line @typescript-eslint/require-await -- async iterable
+const createSource = async function *(input: string[]) {
+  for (const line of input) {
+    yield line;
+  }
+};
+
+const test = async (a: string[], b: string[], expected: boolean) => {
+  expect((await fileEqual(a, createSource(b)))).to.eq(expected);
+};
+
+describe('fileEqual', () => {
+  it('same', () => test(
+    ['A', 'B'],
+    ['A', 'B'],
+    true
+  ));
+
+  it('ignore comment', async () => {
+    await test(
+      ['# A', 'B'],
+      ['# B', 'B'],
+      true
+    );
+
+    await test(
+      ['# A', '# C', 'B'],
+      ['# A', '# D', 'B'],
+      true
+    );
+  });
+
+  it('comment more', () => test(
+    ['# A', 'B'],
+    ['# A', '# B', 'B'],
+    false
+  ));
+
+  it('larger', () => test(
+    ['A', 'B'],
+    ['A', 'B', 'C'],
+    false
+  ));
+
+  it('smaller', () => test(
+    ['A', 'B', 'C'],
+    ['A', 'B'],
+    false
+  ));
+});

Build/lib/create-file.ts

@@ -12,20 +12,13 @@ import { createTrie } from './trie';
 import { pack, unpackFirst, unpackSecond } from './bitwise';
 import { asyncWriteToStream } from './async-write-to-stream';
 
-export async function compareAndWriteFile(span: Span, linesA: string[], filePath: string) {
-  let isEqual = true;
-  const linesALen = linesA.length;
+export const fileEqual = async (linesA: string[], source: AsyncIterable<string>): Promise<boolean> => {
+  if (linesA.length === 0) {
+    return false;
+  }
 
-  if (!fs.existsSync(filePath)) {
-    console.log(`${filePath} does not exists, writing...`);
-    isEqual = false;
-  } else if (linesALen === 0) {
-    console.log(`Nothing to write to ${filePath}...`);
-    isEqual = false;
-  } else {
-    isEqual = await span.traceChildAsync(`comparing ${filePath}`, async () => {
   let index = 0;
-      for await (const lineB of readFileByLine(filePath)) {
+  for await (const lineB of source) {
     const lineA = linesA[index] as string | undefined;
     index++;
 
@@ -53,13 +46,23 @@ export async function compareAndWriteFile(span: Span, linesA: string[], filePath
     }
   }
 
-      if (index !== linesALen) {
+  if (index !== linesA.length) {
     // The file becomes larger
     return false;
   }
 
   return true;
-    });
+};
+
+export async function compareAndWriteFile(span: Span, linesA: string[], filePath: string) {
+  let isEqual = true;
+  const linesALen = linesA.length;
+
+  if (fs.existsSync(filePath)) {
+    isEqual = await fileEqual(linesA, readFileByLine(filePath));
+  } else {
+    console.log(`${filePath} does not exists, writing...`);
+    isEqual = false;
   }
 
   if (isEqual) {