fix: do not fix format errors with --dry-run

src/format.ts

@@ -28,6 +28,11 @@ const baseArgs = ['-style=file'];
  */
 export async function format(
     options: Options, files: string[] = [], fix = false): Promise<boolean> {
+  if (options.dryRun && fix) {
+    options.logger.log('format: skipping auto fix since --dry-run was passed');
+    fix = false;
+  }
+
   const program = createProgram(options);
   // Obtain a list of source files to format.
   // We use program.getRootFileNames to get only the files that match the

test/test-format.ts

@@ -15,6 +15,7 @@
  */
 
 import test from 'ava';
+import fs from 'fs';
 import * as path from 'path';
 
 import {Options} from '../src/cli';
@@ -25,6 +26,7 @@ import {withFixtures} from './fixtures';
 
 // clang-format won't pass this code because of trailing spaces.
 const BAD_CODE = 'export const foo = 2;  ';
+const GOOD_CODE = 'export const foo = 2;';
 
 const OPTIONS: Options = {
   gtsRootDir: path.resolve(__dirname, '../..'),
@@ -35,6 +37,15 @@ const OPTIONS: Options = {
   logger: {log: console.log, error: console.error, dir: nop}
 };
 
+test.serial('format should return false for well-formatted files', t => {
+  return withFixtures(
+      {'tsconfig.json': JSON.stringify({files: ['a.ts']}), 'a.ts': GOOD_CODE},
+      async () => {
+        const result = await format.format(OPTIONS, [], false);
+        t.true(result);
+      });
+});
+
 test.serial('format should return false for ill-formatted files', t => {
   return withFixtures(
       {'tsconfig.json': JSON.stringify({files: ['a.ts']}), 'a.ts': BAD_CODE},
@@ -57,4 +68,99 @@ test.serial('format should only look in root files', t => {
       });
 });
 
-// TODO: Add more tests
+test.serial('format should auto fix problems', t => {
+  return withFixtures(
+      {'tsconfig.json': JSON.stringify({files: ['a.ts']}), 'a.ts': BAD_CODE},
+      async (fixturesDir) => {
+        const result = await format.format(OPTIONS, [], true);
+        t.true(result);
+        const contents =
+            fs.readFileSync(path.join(fixturesDir, 'a.ts'), 'utf8');
+        t.deepEqual(contents, GOOD_CODE);
+      });
+});
+
+test.serial('format should format files listed in tsconfig.files', t => {
+  return withFixtures(
+      {
+        'tsconfig.json': JSON.stringify({files: ['a.ts']}),
+        'a.ts': GOOD_CODE,
+        'b.ts': BAD_CODE
+      },
+      async () => {
+        const okay = await format.format(OPTIONS);
+        t.true(okay);
+      });
+});
+
+test.serial(
+    'format should format *.ts files when no files or inlcude has been specified',
+    async t => {
+      return withFixtures(
+          {
+            'tsconfig.json': JSON.stringify({}),
+            'a.ts': GOOD_CODE,
+            'b.ts': BAD_CODE
+          },
+          async () => {
+            const okay = await format.format(OPTIONS);
+            t.false(okay);
+          });
+    });
+
+test.serial(
+    'format files listed in tsconfig.files when empty list is provided',
+    async t => {
+      return withFixtures(
+          {
+            'tsconfig.json': JSON.stringify({files: ['a.ts']}),
+            'a.ts': BAD_CODE,
+            'b.ts': BAD_CODE
+          },
+          async (fixturesDir) => {
+            const okay = await format.format(OPTIONS, [], true);
+            t.is(okay, true);
+            const contents =
+                fs.readFileSync(path.join(fixturesDir, 'a.ts'), 'utf8');
+            t.deepEqual(contents, GOOD_CODE);
+          });
+    });
+
+test.serial('skip files listed in exclude', t => {
+  return withFixtures(
+      {
+        'tsconfig.json': JSON.stringify({exclude: ['b.*']}),
+        'a.ts': GOOD_CODE,
+        'b.ts': BAD_CODE
+      },
+      async () => {
+        const okay = await format.format(OPTIONS);
+        t.is(okay, true);
+      });
+});
+
+test.serial('format globs listed in include', t => {
+  return withFixtures(
+      {
+        'tsconfig.json': JSON.stringify({include: ['dirb/*']}),
+        dira: {'a.ts': GOOD_CODE},
+        dirb: {'b.ts': BAD_CODE}
+      },
+      async () => {
+        const okay = await format.format(OPTIONS);
+        t.is(okay, false);
+      });
+});
+
+test.serial('format should not auto fix on dry-run', t => {
+  return withFixtures(
+      {'tsconfig.json': JSON.stringify({files: ['a.ts']}), 'a.ts': BAD_CODE},
+      async (fixturesDir) => {
+        const optionsWithDryRun = Object.assign({}, OPTIONS, {dryRun: true});
+        const okay = await format.format(optionsWithDryRun, [], true);
+        t.is(okay, false);
+        const contents =
+            fs.readFileSync(path.join(fixturesDir, 'a.ts'), 'utf8');
+        t.deepEqual(contents, BAD_CODE);
+      });
+});