Fix prettier check in empty files (denoland/deno_std#302)

Original: https://github.com/denoland/deno_std/commit/e5a493e9e8df80abec51c06958dea755e19c40fd

3 files changed, 7 insertions, 3 deletions

diff --git a/prettier/main.ts b/prettier/main.ts
index a5e11e79f..f4a2232cc 100755
--- a/prettier/main.ts
+++ b/prettier/main.ts
@@ -107,8 +107,8 @@ async function checkFile(
   const text = await readFileIfExists(filename);
 
   if (!text) {
-    // The file is deleted. Skip.
-    return;
+    // The file is empty. Skip.
+    return true;
   }
 
   const formatted = prettier.check(text, {
diff --git a/prettier/main_test.ts b/prettier/main_test.ts
index 0d6015080..10ad79e36 100644
--- a/prettier/main_test.ts
+++ b/prettier/main_test.ts
@@ -48,7 +48,11 @@ async function clearTestdataChanges(): Promise<void> {
 test(async function testPrettierCheckAndFormatFiles() {
   await clearTestdataChanges();
 
-  const files = [join(testdata, "0.ts"), join(testdata, "1.js")];
+  const files = [
+    join(testdata, "0.ts"),
+    join(testdata, "1.js"),
+    join(testdata, "2.ts")
+  ];
 
   var { code, stdout } = await run([...cmd, "--check", ...files]);
   assertEquals(code, 1);
diff --git a/prettier/testdata/2.ts b/prettier/testdata/2.ts
new file mode 100644
index 000000000..e69de29bb
--- /dev/null
+++ b/prettier/testdata/2.ts