Move onLine to utilities

This way it can be used by the tests when spawning code-server on a
random port to look for the address.

ci/dev/watch.ts

@@ -2,6 +2,7 @@ import browserify from "browserify"
 import * as cp from "child_process"
 import * as fs from "fs"
 import * as path from "path"
+import { onLine } from "../../src/node/util"
 
 async function main(): Promise<void> {
   try {
@@ -97,38 +98,6 @@ class Watcher {
       path.join(this.rootPath, "out/browser/pages/vscode.js"),
     ]
 
-    // From https://github.com/chalk/ansi-regex
-    const pattern = [
-      "[\\u001B\\u009B][[\\]()#;?]*(?:(?:(?:[a-zA-Z\\d]*(?:;[-a-zA-Z\\d\\/#&.:=?%@~_]*)*)?\\u0007)",
-      "(?:(?:\\d{1,4}(?:;\\d{0,4})*)?[\\dA-PR-TZcf-ntqry=><~]))",
-    ].join("|")
-    const re = new RegExp(pattern, "g")
-
-    /**
-     * Split stdout on newlines and strip ANSI codes.
-     */
-    const onLine = (proc: cp.ChildProcess, callback: (strippedLine: string, originalLine: string) => void): void => {
-      let buffer = ""
-      if (!proc.stdout) {
-        throw new Error("no stdout")
-      }
-      proc.stdout.setEncoding("utf8")
-      proc.stdout.on("data", (d) => {
-        const data = buffer + d
-        const split = data.split("\n")
-        const last = split.length - 1
-
-        for (let i = 0; i < last; ++i) {
-          callback(split[i].replace(re, ""), split[i])
-        }
-
-        // The last item will either be an empty string (the data ended with a
-        // newline) or a partial line (did not end with a newline) and we must
-        // wait to parse it until we get a full line.
-        buffer = split[last]
-      })
-    }
-
     let startingVscode = false
     let startedVscode = false
     onLine(vscode, (line, original) => {

src/node/util.ts

@@ -17,6 +17,38 @@ export interface Paths {
   runtime: string
 }
 
+// From https://github.com/chalk/ansi-regex
+const pattern = [
+  "[\\u001B\\u009B][[\\]()#;?]*(?:(?:(?:[a-zA-Z\\d]*(?:;[-a-zA-Z\\d\\/#&.:=?%@~_]*)*)?\\u0007)",
+  "(?:(?:\\d{1,4}(?:;\\d{0,4})*)?[\\dA-PR-TZcf-ntqry=><~]))",
+].join("|")
+const re = new RegExp(pattern, "g")
+
+/**
+ * Split stdout on newlines and strip ANSI codes.
+ */
+export const onLine = (proc: cp.ChildProcess, callback: (strippedLine: string, originalLine: string) => void): void => {
+  let buffer = ""
+  if (!proc.stdout) {
+    throw new Error("no stdout")
+  }
+  proc.stdout.setEncoding("utf8")
+  proc.stdout.on("data", (d) => {
+    const data = buffer + d
+    const split = data.split("\n")
+    const last = split.length - 1
+
+    for (let i = 0; i < last; ++i) {
+      callback(split[i].replace(re, ""), split[i])
+    }
+
+    // The last item will either be an empty string (the data ended with a
+    // newline) or a partial line (did not end with a newline) and we must
+    // wait to parse it until we get a full line.
+    buffer = split[last]
+  })
+}
+
 export const paths = getEnvPaths()
 
 /**

test/unit/node/util.test.ts

@@ -1,3 +1,5 @@
+import * as cp from "child_process"
+import { generateUuid } from "../../../src/common/util"
 import * as util from "../../../src/node/util"
 
 describe("getEnvPaths", () => {
@@ -397,3 +399,38 @@ describe("sanitizeString", () => {
     expect(util.sanitizeString("   ")).toBe("")
   })
 })
+
+describe("onLine", () => {
+  // Spawn a process that outputs anything given on stdin.
+  let proc: cp.ChildProcess | undefined
+
+  beforeAll(() => {
+    proc = cp.spawn("node", ["-e", 'process.stdin.setEncoding("utf8");process.stdin.on("data", console.log)'])
+  })
+
+  afterAll(() => {
+    proc?.kill()
+  })
+
+  it("should call with individual lines", async () => {
+    const size = 100
+    const received = new Promise<string[]>((resolve) => {
+      const lines: string[] = []
+      util.onLine(proc!, (line) => {
+        lines.push(line)
+        if (lines.length === size) {
+          resolve(lines)
+        }
+      })
+    })
+
+    const expected: string[] = []
+    for (let i = 0; i < size; ++i) {
+      expected.push(generateUuid(i))
+    }
+
+    proc?.stdin?.write(expected.join("\n"))
+
+    expect(await received).toEqual(expected)
+  })
+})