CLI: Skip print code or write file when performance flags found (#12682)

changelog_unreleased/cli/12682.md

@@ -0,0 +1,3 @@
+#### Skip print code or write file when performance flags found (#12682 by @fisker)
+
+When `--debug-benchmark` or `--debug-repeat` is used, the CLI will skip print the formatted code to the screen or write files.

src/cli/format.js

@@ -103,6 +103,16 @@ function listDifferent(context, input, options, filename) {
   return true;
 }
 
+function getPerformanceTestFlag(context) {
+  if (context.argv.debugBenchmark) {
+    return "--debug-benchmark";
+  }
+
+  if (context.argv.debugRepeat > 0) {
+    return "--debug-repeat";
+  }
+}
+
 function format(context, input, opt) {
   if (!opt.parser && !opt.filepath) {
     throw new errors.UndefinedParserError(
@@ -267,7 +277,17 @@ async function formatStdin(context) {
       return;
     }
 
-    writeOutput(context, format(context, input, options), options);
+    const formatted = format(context, input, options);
+
+    const performanceTestFlag = getPerformanceTestFlag(context);
+    if (performanceTestFlag) {
+      context.logger.log(
+        `'${performanceTestFlag}' option found, skipped print code to screen.`
+      );
+      return;
+    }
+
+    writeOutput(context, formatted, options);
   } catch (error) {
     handleError(context, relativeFilepath || "stdin", error);
   }
@@ -280,7 +300,7 @@ async function formatFiles(context) {
 
   let numberOfUnformattedFilesFound = 0;
 
-  if (context.argv.check) {
+  if (context.argv.check && !getPerformanceTestFlag(context)) {
     context.logger.log("Checking formatting...");
   }
 
@@ -369,6 +389,14 @@ async function formatFiles(context) {
       printedFilename.clear();
     }
 
+    const performanceTestFlag = getPerformanceTestFlag(context);
+    if (performanceTestFlag) {
+      context.logger.log(
+        `'${performanceTestFlag}' option found, skipped print code or write files.`
+      );
+      return;
+    }
+
     if (context.argv.write) {
       // Don't write the file if it won't change in order not to invalidate
       // mtime based caches.

tests/integration/__tests__/performance-flags.js

@@ -0,0 +1,63 @@
+"use strict";
+
+const runPrettier = require("../run-prettier.js");
+
+describe("should not write file or print code when `--debug-benchmark` or `--debug-repeat` found", () => {
+  // Can't test `--debug-benchmark`, since it requires `benchmark` package
+  runPrettier(
+    "cli/performance-flags",
+    ["--debug-repeat", "2", "--parser", "babel"],
+    {
+      input: "foo(    bar    )",
+    }
+  ).test({
+    stderr: "",
+    status: 0,
+    stdout: "'--debug-repeat' option found, skipped print code to screen.\n",
+    write: [],
+  });
+
+  runPrettier("cli/performance-flags", [
+    "fixture.js",
+    "--debug-repeat",
+    "2",
+    "--parser",
+    "babel",
+  ]).test({
+    stderr: "",
+    status: 0,
+    stdout:
+      "'--debug-repeat' option found, skipped print code or write files.\n",
+    write: [],
+  });
+
+  runPrettier("cli/performance-flags", [
+    "fixture.js",
+    "--debug-repeat",
+    "2",
+    "--parser",
+    "babel",
+    "--write",
+  ]).test({
+    stderr: "",
+    status: 0,
+    stdout:
+      "'--debug-repeat' option found, skipped print code or write files.\n",
+    write: [],
+  });
+
+  runPrettier("cli/performance-flags", [
+    "fixture.js",
+    "--debug-repeat",
+    "2",
+    "--parser",
+    "babel",
+    "--check",
+  ]).test({
+    stderr: "",
+    status: 0,
+    stdout:
+      "'--debug-repeat' option found, skipped print code or write files.\n",
+    write: [],
+  });
+});

tests/integration/cli/performance-flags/fixture.js

@@ -0,0 +1 @@
+foo(    bar    )