Split fs code from the transform() function

Author: Turbo87

lib/index.js

@@ -4,7 +4,7 @@ const debug = require('debug')('tagless-ember-components-codemod');
 const chalk = require('chalk');
 
 const SilentError = require('./silent-error');
-const { transform } = require('./transform');
+const { transformPath } = require('./transform');
 
 async function run() {
   let path = await pkgDir();
@@ -24,7 +24,7 @@ async function runForPath(path, options = {}) {
 
   for (let path of paths) {
     try {
-      let tagName = transform(path);
+      let tagName = transformPath(path);
       if (tagName) {
         log(chalk.green(`${chalk.dim(path)}: <${tagName}>...</${tagName}>`));
       } else {

lib/transform.js

@@ -2,7 +2,7 @@ const fs = require('fs');
 const path = require('path');
 const templateRecast = require('ember-template-recast');
 const j = require('jscodeshift').withParser('ts');
-const debug = require('debug')('tagless-ember-components-codemod');
+const _debug = require('debug')('tagless-ember-components-codemod');
 
 const SilentError = require('./silent-error');
 
@@ -46,17 +46,31 @@ const EVENT_HANDLER_METHODS = [
   'drop',
 ];
 
-function transform(componentPath) {
-  let source = fs.readFileSync(componentPath, 'utf8');
+function transformPath(componentPath) {
+  let debug = (fmt, ...args) => _debug(`${componentPath}: ${fmt}`, ...args);
 
   let templatePath = guessTemplatePath(componentPath);
   if (!fs.existsSync(templatePath)) {
     throw new SilentError(`Could not find template at ${templatePath}`);
   }
-  debug(`${componentPath}: templatePath: %o`, templatePath);
+  debug('templatePath: %o', templatePath);
 
+  let source = fs.readFileSync(componentPath, 'utf8');
   let template = fs.readFileSync(templatePath, 'utf8');
 
+  let result = transform(source, template, { debug });
+
+  if (result.tagName) {
+    fs.writeFileSync(componentPath, result.source, 'utf8');
+    fs.writeFileSync(templatePath, result.template, 'utf8');
+  }
+
+  return result.tagName;
+}
+
+function transform(source, template, options = {}) {
+  let debug = options.debug || _debug;
+
   let root = j(source);
 
   // find `export default Component.extend({ ... });` AST node
@@ -95,11 +109,11 @@ function transform(componentPath) {
 
   // skip tagless components (silent)
   if (tagName === '') {
-    debug(`${componentPath}: tagName: %o -> skip`, tagName);
-    return;
+    debug('tagName: %o -> skip', tagName);
+    return { source, template };
   }
 
-  debug(`${componentPath}: tagName: %o`, tagName);
+  debug('tagName: %o', tagName);
 
   // skip components that use `this.element`
   let thisElementPaths = j(objectArg).find(j.MemberExpression, {
@@ -120,16 +134,16 @@ function transform(componentPath) {
 
   // analyze `elementId`, `attributeBindings`, `classNames` and `classNameBindings`
   let elementId = findElementId(properties);
-  debug(`${componentPath}: elementId: %o`, elementId);
+  debug('elementId: %o', elementId);
 
   let attributeBindings = findAttributeBindings(properties);
-  debug(`${componentPath}: attributeBindings: %o`, attributeBindings);
+  debug('attributeBindings: %o', attributeBindings);
 
   let classNames = findClassNames(properties);
-  debug(`${componentPath}: classNames: %o`, classNames);
+  debug('classNames: %o', classNames);
 
   let classNameBindings = findClassNameBindings(properties);
-  debug(`${componentPath}: classNameBindings: %o`, classNameBindings);
+  debug('classNameBindings: %o', classNameBindings);
 
   let templateAST = templateRecast.parse(template);
 
@@ -158,7 +172,7 @@ function transform(componentPath) {
     )
     .remove();
 
-  fs.writeFileSync(componentPath, root.toSource(), 'utf8');
+  let newSource = root.toSource();
 
   // wrap existing template with root element
   let classNodes = [];
@@ -200,9 +214,9 @@ function transform(componentPath) {
     }),
   ];
 
-  fs.writeFileSync(templatePath, templateRecast.print(templateAST), 'utf8');
+  let newTemplate = templateRecast.print(templateAST);
 
-  return tagName;
+  return { source: newSource, template: newTemplate, tagName };
 }
 
 function isProperty(path, name) {
@@ -301,6 +315,7 @@ function guessTemplatePath(componentPath) {
 
 module.exports = {
   transform,
+  transformPath,
   findTagName,
   findElementId,
   findAttributeBindings,