Bug 1699391: Add a spinner to the console output while setting up python virtual env

CHANGELOG.md

@@ -5,6 +5,7 @@
 * [#260](https://github.com/mozilla/glean.js/pull/260): Set minimum node (>= 12.0.0) and npm (>= 7.0.0) versions.
 * [#202](https://github.com/mozilla/glean.js/pull/202): Add a testing API for the ping type.
 * [#253](https://github.com/mozilla/glean.js/pull/253): Implement the timespan metric type.
+* [#261](https://github.com/mozilla/glean.js/pull/261): Show a spinner while setting up python virtual environment
 
 # v0.10.2 (2021-04-26)
 

glean/src/cli.ts

@@ -137,10 +137,12 @@ async function createPythonVenv(venvPath: string): Promise<boolean> {
   const venvCmd = `${getSystemPythonBinName()} -m venv ${VIRTUAL_ENVIRONMENT_DIR}`;
 
   for (const cmd of [venvCmd, pipCmd]) {
+    const spinner = getStartedSpinner();
     const {err, stdout, stderr} = await new Promise<{err: exec.ExecException | null, stdout: string, stderr: string}>(resolve => {
       exec.exec(cmd, (err, stdout, stderr) => resolve({err, stdout, stderr}));
     });
 
+    stopSpinner(spinner);
     console.log(`${stdout}`);
 
     if (err) {
@@ -176,6 +178,7 @@ async function setup(projectRoot: string) {
  * @param parserArgs the list of arguments passed to this command.
  */
 async function runGlean(projectRoot: string, parserArgs: string[]) {
+  const spinner = getStartedSpinner();
   const venvRoot = path.join(projectRoot, VIRTUAL_ENVIRONMENT_DIR);
   const pythonBin = path.join(getPythonVenvBinariesPath(venvRoot), getSystemPythonBinName());
   const cmd = `${pythonBin} -c "${PYTHON_SCRIPT}" online glean_parser ${GLEAN_PARSER_VERSION} ${parserArgs.join(" ")}`;
@@ -184,6 +187,7 @@ async function runGlean(projectRoot: string, parserArgs: string[]) {
     exec.exec(cmd, (err, stdout, stderr) => resolve({err, stdout, stderr}));
   });
 
+  stopSpinner(spinner);
   console.log(`${stdout}`);
 
   if (err) {
@@ -214,3 +218,27 @@ async function run(args: string[]) {
 run(argv).catch(e => {
   console.error("There was an error running Glean", e);
 });
+
+/**
+ * Returns a spinner
+ *
+ * @returns an Interval ID that logs certain characters
+ */
+function getStartedSpinner() {
+  const ticks = ["\\", "|", "/", "-"];
+  let i = 0;
+  return setInterval(function() {
+    process.stdout.write(" "+ticks[i++]+"\r\r");
+    i %= 4;
+  }, 250);
+}
+
+/**
+ * Stops the spinner
+ *
+ * @param spinner is created by getStartedSpinner
+ */
+function stopSpinner(spinner: NodeJS.Timeout) {
+  process.stdout.write("  \r");
+  clearInterval(spinner);
+}