Add test for multi-chunk lines

tests/test.js

@@ -553,7 +553,7 @@ const TESTS = [
 ]
 
 for (const {args, expected} of TESTS) {
-  const flags =      args.filter(arg =>  arg.startsWith('-'))
+  const flags      = args.filter(arg =>  arg.startsWith('-'))
   const parameters = args.filter(arg => !arg.startsWith('-'))
   for (const args of reorderings(parameters, flags)) {
     test(`grep ${args.join(' ')}`, async t => {
@@ -593,12 +593,26 @@ test('grep stdin', async t => {
 })
 
 // Ensure that the streams deal with lines spread across chunks correctly
-test('multiple chunk input file', async t => {
+test('multiple-chunk input file', async t => {
   const lines = new Array(1e5).fill().map((_, i) => `Line ${i + 1}`)
   for (let i = 0; i < 10; i++) {
     const search = `${i}`
-    const {stdout} = await execFilePromise('node', ['../grep.js', search, 'files/long.txt'])
+    const {stdout} = await execFilePromise(
+      'node', ['../grep.js', search, 'files/long.txt']
+    )
     const expectedLines = lines.filter(line => line.includes(search))
     t.deepEqual(stdout, expectedLines.map(line => `${line}\n`).join(''))
   }
 })
+
+// Ensure that the streams deal with lines containing multiple chunks
+test('multiple-chunk lines', async t => {
+  const contents = await fs.promises.readFile('files/long-lines.txt', 'utf8')
+  const lines = contents.trim().split('\n')
+  for (let i = 0; i < 10; i++) {
+    const {stdout} = await execFilePromise(
+      'node', ['../grep.js', `${i}`, 'files/long-lines.txt']
+    )
+    t.deepEqual(stdout, lines[i] + '\n')
+  }
+})