fix(cli): do not early exit for `--debug-check` (#2987)

* test: add failing test

* fix(cli): do not early exit for `--debug-check`

src/cli-util.js

@@ -58,14 +58,12 @@ function handleError(filename, error) {
   // parser has mistakenly thrown arrays sometimes.)
   if (isParseError) {
     console.error(`${filename}: ${String(error)}`);
-  } else if (
-    isValidationError ||
-    error instanceof errors.ConfigError ||
-    error instanceof errors.DebugError
-  ) {
+  } else if (isValidationError || error instanceof errors.ConfigError) {
     console.error(String(error));
     // If validation fails for one file, it will fail for all of them.
     process.exit(1);
+  } else if (error instanceof errors.DebugError) {
+    console.error(`${filename}: ${error.message}`);
   } else {
     console.error(filename + ":", error.stack || error);
   }

tests_integration/__tests__/__snapshots__/debug-check.js.snap

@@ -3,3 +3,65 @@
 exports[`checks stdin with --debug-check (write) 1`] = `Array []`;
 
 exports[`doesn't crash when --debug-check is passed (write) 1`] = `Array []`;
+
+exports[`show diff for 2+ error files with --debug-check (stderr) 1`] = `
+"a.js: ast(input) !== ast(prettier(input))
+Index: 
+===================================================================
+--- 	
++++ 	
+@@ -17,6 +17,6 @@
+                   \\"method\\": false,
+                   \\"key\\": {
+-                    \\"type\\": \\"StringLiteral\\",
+-                    \\"value\\": \\"a\\"
++                    \\"type\\": \\"Identifier\\",
++                    \\"name\\": \\"a\\"
+                   },
+                   \\"computed\\": false,
+
+Index: 
+===================================================================
+--- 	
++++ 	
+@@ -1,3 +1,3 @@
+ const a = {
+-    'a': 1
++  a: 1
+ };
+
+b.js: ast(input) !== ast(prettier(input))
+Index: 
+===================================================================
+--- 	
++++ 	
+@@ -17,6 +17,6 @@
+                   \\"method\\": false,
+                   \\"key\\": {
+-                    \\"type\\": \\"StringLiteral\\",
+-                    \\"value\\": \\"b\\"
++                    \\"type\\": \\"Identifier\\",
++                    \\"name\\": \\"b\\"
+                   },
+                   \\"computed\\": false,
+
+Index: 
+===================================================================
+--- 	
++++ 	
+@@ -1,3 +1,3 @@
+ const b = {
+-    'b': 2
++  b: 2
+ };
+
+"
+`;
+
+exports[`show diff for 2+ error files with --debug-check (stdout) 1`] = `
+"
+
+"
+`;
+
+exports[`show diff for 2+ error files with --debug-check (write) 1`] = `Array []`;

tests_integration/__tests__/debug-check.js

@@ -19,3 +19,9 @@ describe("checks stdin with --debug-check", () => {
     status: 0
   });
 });
+
+describe("show diff for 2+ error files with --debug-check", () => {
+  runPrettier("cli/debug-check", ["*.js", "--debug-check"]).test({
+    status: "non-zero"
+  });
+});

tests_integration/cli/debug-check/a.js

@@ -0,0 +1,3 @@
+const a = {
+    'a': 1
+};

tests_integration/cli/debug-check/b.js

@@ -0,0 +1,3 @@
+const b = {
+    'b': 2
+};