Log after subsequent compilations in --watch mode

packages/babel-cli/src/babel/dir.js

@@ -1,6 +1,7 @@
 // @flow
 
 import defaults from "lodash/defaults";
+import debounce from "lodash/debounce";
 import { sync as makeDirSync } from "make-dir";
 import slash from "slash";
 import path from "path";
@@ -138,24 +139,50 @@ export default async function({
     }
   }
 
+  let compiledFiles = 0;
+  let startTime = null;
+
+  const logSuccess = debounce(
+    function() {
+      if (startTime === null) {
+        // This should never happen, but just in case it's better
+        // to ignore the log message rather than making @babel/cli crash.
+        return;
+      }
+
+      const diff = process.hrtime(startTime);
+
+      console.log(
+        `Successfully compiled ${compiledFiles} ${
+          compiledFiles !== 1 ? "files" : "file"
+        } with Babel (${diff[0] * 1e3 + Math.round(diff[1] / 1e6)}ms).`,
+      );
+      compiledFiles = 0;
+      startTime = null;
+    },
+    100,
+    { trailing: true },
+  );
+
   if (!cliOptions.skipInitialBuild) {
     if (cliOptions.deleteDirOnStart) {
       util.deleteDir(cliOptions.outDir);
     }
 
     makeDirSync(cliOptions.outDir);
 
-    let compiledFiles = 0;
+    startTime = process.hrtime();
+
     for (const filename of cliOptions.filenames) {
+      // compiledFiles is just incremented without reading its value, so we
+      // don't risk race conditions.
+      // eslint-disable-next-line require-atomic-updates
       compiledFiles += await handle(filename);
     }
 
     if (!cliOptions.quiet) {
-      console.log(
-        `Successfully compiled ${compiledFiles} ${
-          compiledFiles !== 1 ? "files" : "file"
-        } with Babel.`,
-      );
+      logSuccess();
+      logSuccess.flush();
     }
   }
 
@@ -172,16 +199,30 @@ export default async function({
         },
       });
 
+      // This, alongside with debounce, allows us to only log
+      // when we are sure that all the files have been compiled.
+      let processing = 0;
+
       ["add", "change"].forEach(function(type: string): void {
-        watcher.on(type, function(filename: string): void {
-          handleFile(
-            filename,
-            filename === filenameOrDir
-              ? path.dirname(filenameOrDir)
-              : filenameOrDir,
-          ).catch(err => {
+        watcher.on(type, async function(filename: string) {
+          processing++;
+          if (startTime === null) startTime = process.hrtime();
+
+          try {
+            await handleFile(
+              filename,
+              filename === filenameOrDir
+                ? path.dirname(filenameOrDir)
+                : filenameOrDir,
+            );
+
+            compiledFiles++;
+          } catch (err) {
             console.error(err);
-          });
+          }
+
+          processing--;
+          if (processing === 0 && !cliOptions.quiet) logSuccess();
         });
       });
     });

packages/babel-cli/test/fixtures/babel/--config-file babelrc nocomment/stdout.txt

@@ -2,4 +2,4 @@
 
 arr.map(function (x) {
   return x * MULTIPLIER;
-});
+});

packages/babel-cli/test/fixtures/babel/--copy-files --include-dotfiles with ignore in babelrc/stdout.txt

@@ -1,2 +1,2 @@
 src/index.js -> lib/index.js
-Successfully compiled 1 file with Babel.
+Successfully compiled 1 file with Babel (123ms).

packages/babel-cli/test/fixtures/babel/--copy-files --include-dotfiles with ignore/stdout.txt

@@ -1,2 +1,2 @@
 src/index.js -> lib/index.js
-Successfully compiled 1 file with Babel.
+Successfully compiled 1 file with Babel (123ms).

packages/babel-cli/test/fixtures/babel/--copy-files --include-dotfiles with only/stdout.txt

@@ -1,3 +1,3 @@
 src/foo/.foo.js -> lib/foo/.foo.js
 src/foo/bar.js -> lib/foo/bar.js
-Successfully compiled 2 files with Babel.
+Successfully compiled 2 files with Babel (123ms).

packages/babel-cli/test/fixtures/babel/--copy-files --include-dotfiles/stdout.txt

@@ -1,4 +1,4 @@
 src/.foo.js -> lib/.foo.js
 src/bar/index.js -> lib/bar/index.js
 src/foo/foo.js -> lib/foo/foo.js
-Successfully compiled 3 files with Babel.
+Successfully compiled 3 files with Babel (123ms).

packages/babel-cli/test/fixtures/babel/--copy-files --no-copy-ignored with babelignore/stdout.txt

@@ -1,2 +1,2 @@
 src/index.js -> lib/index.js
-Successfully compiled 1 file with Babel.
+Successfully compiled 1 file with Babel (123ms).

packages/babel-cli/test/fixtures/babel/--copy-files --no-copy-ignored with ignore in babelrc/stdout.txt

@@ -1,2 +1,2 @@
 src/index.js -> lib/index.js
-Successfully compiled 1 file with Babel.
+Successfully compiled 1 file with Babel (123ms).

packages/babel-cli/test/fixtures/babel/--copy-files --no-copy-ignored with ignore/stdout.txt

@@ -1,2 +1,2 @@
 src/index.js -> lib/index.js
-Successfully compiled 1 file with Babel.
+Successfully compiled 1 file with Babel (123ms).

packages/babel-cli/test/fixtures/babel/--copy-files --no-copy-ignored with only/stdout.txt

@@ -1,2 +1,2 @@
 src/foo/bar.js -> lib/foo/bar.js
-Successfully compiled 1 file with Babel.
+Successfully compiled 1 file with Babel (123ms).

packages/babel-cli/test/fixtures/babel/--copy-files with ignore in babelignore/stdout.txt

@@ -1,2 +1,2 @@
 src/index.js -> lib/index.js
-Successfully compiled 1 file with Babel.
+Successfully compiled 1 file with Babel (123ms).

packages/babel-cli/test/fixtures/babel/--copy-files with ignore in babelrc/stdout.txt

@@ -1,2 +1,2 @@
 src/index.js -> lib/index.js
-Successfully compiled 1 file with Babel.
+Successfully compiled 1 file with Babel (123ms).

packages/babel-cli/test/fixtures/babel/--copy-files with ignore/stdout.txt

@@ -1,2 +1,2 @@
 src/index.js -> lib/index.js
-Successfully compiled 1 file with Babel.
+Successfully compiled 1 file with Babel (123ms).

packages/babel-cli/test/fixtures/babel/--copy-files with only/stdout.txt

@@ -1,2 +1,2 @@
 src/foo/bar.js -> lib/foo/bar.js
-Successfully compiled 1 file with Babel.
+Successfully compiled 1 file with Babel (123ms).

packages/babel-cli/test/fixtures/babel/--copy-files/stdout.txt

@@ -1,3 +1,3 @@
 src/bar/index.js -> lib/bar/index.js
 src/foo/foo.js -> lib/foo/foo.js
-Successfully compiled 2 files with Babel.
+Successfully compiled 2 files with Babel (123ms).

packages/babel-cli/test/fixtures/babel/--ignore complete/stdout.txt

@@ -1,2 +1,2 @@
 src/foobar/foo.js -> lib/foobar/foo.js
-Successfully compiled 1 file with Babel.
+Successfully compiled 1 file with Babel (123ms).

packages/babel-cli/test/fixtures/babel/--ignore glob/stdout.txt

@@ -2,4 +2,4 @@ src/a.js -> lib/a.js
 src/b.js -> lib/b.js
 src/baz/c.js -> lib/baz/c.js
 src/foo.js -> lib/foo.js
-Successfully compiled 4 files with Babel.
+Successfully compiled 4 files with Babel (123ms).

packages/babel-cli/test/fixtures/babel/--ignore/stdout.txt

@@ -1,2 +1,2 @@
 src/bar/index.js -> lib/bar/index.js
-Successfully compiled 1 file with Babel.
+Successfully compiled 1 file with Babel (123ms).

packages/babel-cli/test/fixtures/babel/--only glob/stdout.txt

@@ -1,3 +1,3 @@
 src/a.foo.js -> lib/a.foo.js
 src/baz/b.foo.js -> lib/baz/b.foo.js
-Successfully compiled 2 files with Babel.
+Successfully compiled 2 files with Babel (123ms).

packages/babel-cli/test/fixtures/babel/--only/stdout.txt

@@ -1,2 +1,2 @@
 src/bar/index.js -> lib/bar/index.js
-Successfully compiled 1 file with Babel.
+Successfully compiled 1 file with Babel (123ms).

packages/babel-cli/test/fixtures/babel/dir --out-dir --copy-files/stdout.txt

@@ -1,2 +1,2 @@
 src/foo.js -> lib/foo.js
-Successfully compiled 1 file with Babel.
+Successfully compiled 1 file with Babel (123ms).

packages/babel-cli/test/fixtures/babel/dir --out-dir --keep-file-extension/stdout.txt

@@ -1,3 +1,3 @@
 src/bar.mjs -> lib/bar.mjs
 src/foo.js -> lib/foo.js
-Successfully compiled 2 files with Babel.
+Successfully compiled 2 files with Babel (123ms).

packages/babel-cli/test/fixtures/babel/dir --out-dir --out-file-extension/stdout.txt

@@ -1,3 +1,3 @@
 src/bar.mjs -> lib/bar.mjs
 src/foo.jsx -> lib/foo.mjs
-Successfully compiled 2 files with Babel.
+Successfully compiled 2 files with Babel (123ms).

packages/babel-cli/test/fixtures/babel/dir --out-dir --relative/stdout.txt

@@ -2,4 +2,4 @@ package1/src/bar/bar1.js -> package1/lib/bar/bar1.js
 package1/src/foo1.js -> package1/lib/foo1.js
 package2/src/bar/bar2.js -> package2/lib/bar/bar2.js
 package2/src/foo2.js -> package2/lib/foo2.js
-Successfully compiled 4 files with Babel.
+Successfully compiled 4 files with Babel (123ms).

packages/babel-cli/test/fixtures/babel/dir --out-dir --source-maps inline/stdout.txt

@@ -1,3 +1,3 @@
 src/bar/bar.js -> lib/bar/bar.js
 src/foo.js -> lib/foo.js
-Successfully compiled 2 files with Babel.
+Successfully compiled 2 files with Babel (123ms).

packages/babel-cli/test/fixtures/babel/dir --out-dir --source-maps/stdout.txt

@@ -1,3 +1,3 @@
 src/bar/bar.js -> lib/bar/bar.js
 src/foo.js -> lib/foo.js
-Successfully compiled 2 files with Babel.
+Successfully compiled 2 files with Babel (123ms).

packages/babel-cli/test/fixtures/babel/dir --out-dir --verbose/stdout.txt

@@ -1,3 +1,3 @@
 src/bar/bar.js -> lib/bar/bar.js
 src/foo.js -> lib/foo.js
-Successfully compiled 2 files with Babel.
+Successfully compiled 2 files with Babel (123ms).

packages/babel-cli/test/fixtures/babel/dir --out-dir/stdout.txt

@@ -1 +1 @@
-Successfully compiled 2 files with Babel.
+Successfully compiled 2 files with Babel (123ms).

packages/babel-cli/test/fixtures/babel/empty dir --out-dir/stdout.txt

@@ -1 +1 @@
-Successfully compiled 0 files with Babel.
+Successfully compiled 0 files with Babel (123ms).

packages/babel-cli/test/fixtures/babel/filename --out-dir --relative/stdout.txt

@@ -1,2 +1,2 @@
 src/foo.js -> lib/foo.js
-Successfully compiled 1 file with Babel.
+Successfully compiled 1 file with Babel (123ms).

packages/babel-cli/test/fixtures/babel/filename --out-dir/stdout.txt

@@ -1,2 +1,2 @@
 src/foo.js -> lib/foo.js
-Successfully compiled 1 file with Babel.
+Successfully compiled 1 file with Babel (123ms).

packages/babel-cli/test/index.js

@@ -49,19 +49,19 @@ const saveInFiles = function(files) {
   });
 };
 
-const replacePaths = function(str, cwd) {
+const normalizeOutput = function(str, cwd) {
   let prev;
   do {
     prev = str;
     str = str.replace(cwd, "<CWD>");
   } while (str !== prev);
 
-  return str;
+  return str.replace(/\(\d+ms\)/g, "(123ms)");
 };
 
 const assertTest = function(stdout, stderr, opts, cwd) {
-  stdout = replacePaths(stdout, cwd);
-  stderr = replacePaths(stderr, cwd);
+  stdout = normalizeOutput(stdout, cwd);
+  stderr = normalizeOutput(stderr, cwd);
 
   const expectStderr = opts.stderr.trim();
   stderr = stderr.trim();
@@ -84,6 +84,7 @@ const assertTest = function(stdout, stderr, opts, cwd) {
     if (opts.stdoutContains) {
       expect(stdout).toContain(expectStdout);
     } else {
+      fs.writeFileSync(opts.stdoutPath, stdout + "\n");
       expect(stdout).toBe(expectStdout);
     }
   } else if (stdout) {
@@ -230,6 +231,7 @@ fs.readdirSync(fixtureLoc).forEach(function(binName) {
 
       ["stdout", "stdin", "stderr"].forEach(function(key) {
         const loc = path.join(testLoc, key + ".txt");
+        opts[key + "Path"] = loc;
         if (fs.existsSync(loc)) {
           opts[key] = helper.readFile(loc);
         } else {