Fix path separators passed to grep

tests/test.js

 const fs = require('fs')
 const test = require('ava')
-const {execFilePromise, matchOutput, reorderings, updateExpectedPaths} = require('./util')
+const {
+  execFilePromise, matchOutput, reorderings, updateExpectedPaths, updatePath
+} = require('./util')
 
 // We are going to run the server directly, not through npm
 const {INIT_CWD, ...GREP_ENV} = process.env
@@ -557,6 +559,8 @@ const TESTS = [
 for (const {args, expected} of TESTS) {
   const flags      = args.filter(arg =>  arg.startsWith('-'))
   const parameters = args.filter(arg => !arg.startsWith('-'))
+  // Update all paths in the parameters to have correct separators
+  for (let i = 1; i < parameters.length; i++) parameters[i] = updatePath(parameters[i])
   for (const args of reorderings(parameters, flags)) {
     test(`grep ${args.join(' ')}`, async t => {
       const {stdout} = await execFilePromise(
@@ -573,7 +577,7 @@ test('grep no matches', async t => {
   let stdout
   try {
     ({stdout} = await execFilePromise(
-      'node', ['../grep.js', 'no-such-string', 'files/independence.txt'],
+      'node', ['../grep.js', 'no-such-string', updatePath('files/independence.txt')],
       {env: GREP_ENV}
     ))
   }
@@ -606,7 +610,7 @@ test('multiple-chunk input file', async t => {
   for (let i = 0; i < 10; i++) {
     const search = `${i}`
     const {stdout} = await execFilePromise(
-      'node', ['../grep.js', search, 'files/long.txt'],
+      'node', ['../grep.js', search, updatePath('files/long.txt')],
       {env: GREP_ENV}
     )
     const expectedLines = lines.filter(line => line.includes(search))
@@ -620,7 +624,7 @@ test('multiple-chunk lines', async t => {
   const lines = contents.trim().split('\n')
   for (let i = 0; i < 10; i++) {
     const {stdout} = await execFilePromise(
-      'node', ['../grep.js', `${i}`, 'files/long-lines.txt'],
+      'node', ['../grep.js', `${i}`, updatePath('files/long-lines.txt')],
       {env: GREP_ENV}
     )
     t.deepEqual(stdout, lines[i] + '\n')

tests/util.js

@@ -17,12 +17,15 @@ function* reorderings(fixed, reorderable) {
 }
 exports.reorderings = reorderings
 
+const updatePath = filename => path.join(...filename.split('/'))
+exports.updatePath = updatePath
+
 /** Updates the path separators in an expected output to match the OS's separator */
 exports.updateExpectedPaths = expected =>
   expected.map(lineGroup => lineGroup.map(line => {
     const pathEnd = line.indexOf(':')
     if (pathEnd < 0) throw new Error('Line does not have a path')
-    return path.join(...line.slice(0, pathEnd).split('/')) + line.slice(pathEnd)
+    return updatePath(line.slice(0, pathEnd)) + line.slice(pathEnd)
   }))
 
 function toLines(text) {