feat(cli): add "--ignore-existing" option

Closes #182

Author: gregberge

__fixtures__/simple-existing/File.js

@@ -0,0 +1 @@
+// nothing

packages/cli/src/__snapshots__/index.test.js.snap

@@ -377,19 +377,19 @@ export default SvgFile
 exports[`cli should suppress output when transforming a directory with a --silent option 1`] = `""`;
 
 exports[`cli should transform a whole directory and output relative destination paths 1`] = `
-"
-__fixtures__/cased/PascalCase.svg -> __fixtures_build__/whole/cased/PascalCase.js
-__fixtures__/cased/camelCase.svg -> __fixtures_build__/whole/cased/CamelCase.js
-__fixtures__/cased/kebab-case.svg -> __fixtures_build__/whole/cased/KebabCase.js
-__fixtures__/cased/multiple---dashes.svg -> __fixtures_build__/whole/cased/MultipleDashes.js
-__fixtures__/complex/skype.svg -> __fixtures_build__/whole/complex/Skype.js
-__fixtures__/complex/telegram.svg -> __fixtures_build__/whole/complex/Telegram.js
-__fixtures__/nesting/a/two.svg -> __fixtures_build__/whole/nesting/a/Two.js
-__fixtures__/nesting/one.svg -> __fixtures_build__/whole/nesting/One.js
-__fixtures__/simple/file.svg -> __fixtures_build__/whole/simple/File.js
-__fixtures__/withPrettierRc/file.svg -> __fixtures_build__/whole/withPrettierRc/File.js
-__fixtures__/withSvgoYml/file.svg -> __fixtures_build__/whole/withSvgoYml/File.js
-__fixtures__/withSvgrRc/file.svg -> __fixtures_build__/whole/withSvgrRc/File.js"
+"[37m[39m
+[37m[39m[37m__fixtures__/cased/camelCase.svg -> __fixtures_build__/whole/cased/CamelCase.js[39m
+[37m[39m[37m__fixtures__/cased/kebab-case.svg -> __fixtures_build__/whole/cased/KebabCase.js[39m
+[37m[39m[37m__fixtures__/cased/multiple---dashes.svg -> __fixtures_build__/whole/cased/MultipleDashes.js[39m
+[37m[39m[37m__fixtures__/complex/skype.svg -> __fixtures_build__/whole/complex/Skype.js[39m
+[37m[39m[37m__fixtures__/complex/telegram.svg -> __fixtures_build__/whole/complex/Telegram.js[39m
+[37m[39m[37m__fixtures__/nesting/a/two.svg -> __fixtures_build__/whole/nesting/a/Two.js[39m
+[37m[39m[37m__fixtures__/nesting/one.svg -> __fixtures_build__/whole/nesting/One.js[39m
+[37m[39m[37m__fixtures__/simple/file.svg -> __fixtures_build__/whole/simple/File.js[39m
+[37m[39m[37m__fixtures__/withPrettierRc/file.svg -> __fixtures_build__/whole/withPrettierRc/File.js[39m
+[37m[39m[37m__fixtures__/withSvgoYml/file.svg -> __fixtures_build__/whole/withSvgoYml/File.js[39m
+[37m[39m[37m__fixtures__/withSvgrRc/file.svg -> __fixtures_build__/whole/withSvgrRc/File.js[39m
+[37m__fixtures__/cased/PascalCase.svg -> __fixtures_build__/whole/cased/PascalCase.js[39m"
 `;
 
 exports[`cli should work with a simple file 1`] = `

packages/cli/src/dirCommand.js

@@ -1,9 +1,23 @@
 /* eslint-disable no-underscore-dangle, no-console */
+import fs from 'fs'
+import { promisify } from 'util'
 import path from 'path'
+import chalk from 'chalk'
 import outputFileSync from 'output-file-sync'
 import readdir from 'recursive-readdir'
 import { convertFile, stat, transformFilename, CASE, politeWrite } from './util'
 
+const access = promisify(fs.access)
+
+async function exists(file) {
+  try {
+    await access(file)
+    return true
+  } catch (error) {
+    return false
+  }
+}
+
 function rename(relative, ext, filenameCase) {
   const relativePath = path.parse(relative)
   relativePath.ext = `.${ext}`
@@ -26,14 +40,25 @@ async function dirCommand(
   { ext = 'js', filenameCase = CASE.PASCAL, ...options },
 ) {
   async function write(src, relative) {
-    if (!isCompilable(relative)) return false
+    if (!isCompilable(relative)) return
     relative = rename(relative, ext, filenameCase)
 
     const dest = path.resolve(program.outDir, relative)
     const code = await convertFile(src, options)
+
+    if (program.ignoreExisting && (await exists(dest))) {
+      politeWrite(
+        program,
+        chalk.grey(`${src} -> ${path.relative(process.cwd(), dest)}\n`),
+      )
+      return
+    }
+
     outputFileSync(dest, code)
-    politeWrite(program, `${src} -> ${path.relative(process.cwd(), dest)}\n`)
-    return true
+    politeWrite(
+      program,
+      chalk.white(`${src} -> ${path.relative(process.cwd(), dest)}\n`),
+    )
   }
 
   async function handle(filename) {

packages/cli/src/index.js

@@ -43,6 +43,7 @@ program
     'disable runtime config (".svgrrc", ".svgo.yml", ".prettierrc")',
   )
   .option('-d, --out-dir <dirname>', 'output files into a directory')
+  .option('--ignore-existing', 'ignore existing files in output directory')
   .option('--ext <ext>', 'specify a custom file extension (default: "js")')
   .option(
     '--filename-case <case>',

packages/cli/src/index.test.js

@@ -58,7 +58,9 @@ describe('cli', () => {
   }, 10000)
 
   it('should suppress output when transforming a directory with a --silent option', async () => {
-    const result = await cli('--silent --out-dir __fixtures_build__/whole __fixtures__')
+    const result = await cli(
+      '--silent --out-dir __fixtures_build__/whole __fixtures__',
+    )
     const sorted = result
       .split(/\n/)
       .sort()
@@ -143,6 +145,14 @@ describe('cli', () => {
     expect(await readdir(outDir)).toMatchSnapshot()
   }, 10000)
 
+  it('should support "--ignore-existing"', async () => {
+    const inDir = '__fixtures__/simple'
+    const outDir = '__fixtures__/simple-existing'
+    await cli(`${inDir} --out-dir=${outDir} --ignore-existing`)
+    const content = fs.readFileSync(path.join(outDir, 'File.js'), 'utf-8')
+    expect(content).toBe('// nothing')
+  }, 10000)
+
   it('should not override config with cli defaults', async () => {
     const result = await cli(
       '__fixtures__/simple/file.svg --config-file=__fixtures__/overrides.config.js',

packages/cli/src/util.js

@@ -53,6 +53,6 @@ export function exitError(error) {
 
 export function politeWrite(program, data) {
   if (!program.silent) {
-    process.stdout.write(data);
+    process.stdout.write(data)
   }
 }