feat: allow extending partials (#213)

lib/util/template.js

@@ -10,7 +10,21 @@ const partialName = (s) => basename(s, extname(s)) // remove extension
   .replace(/^_/, '') // remove leading underscore
   .replace(/-([a-z])/g, (_, g) => g.toUpperCase()) // camelcase
 
-const setupHandlebars = (...partialDirs) => {
+const makePartials = (dir, setDefault) => {
+  const partials = fs.readdirSync(dir).reduce((acc, f) => {
+    const partial = fs.readFileSync(join(dir, f)).toString()
+    const name = partialName(f)
+    acc[name] = partial
+    if (setDefault && f.startsWith('_')) {
+      acc[partialName(`default-${name}`)] = partial
+    }
+    return acc
+  }, {})
+
+  Handlebars.registerPartial(partials)
+}
+
+const setupHandlebars = (baseDir, ...otherDirs) => {
   Handlebars.registerHelper('obj', ({ hash }) => Object.fromEntries(safeValues(hash)))
   Handlebars.registerHelper('join', (arr, sep) => arr.join(typeof sep === 'string' ? sep : ', '))
   Handlebars.registerHelper('pluck', (arr, key) => arr.map(a => a[key]))
@@ -20,21 +34,9 @@ const setupHandlebars = (...partialDirs) => {
   Handlebars.registerHelper('json', (c) => JSON.stringify(c))
   Handlebars.registerHelper('del', () => JSON.stringify(DELETE))
 
-  // Load all files as camelcase partial names.
-  // all other content dirs only get special underscore leading
-  // files as partials. this prevents recursion loops when overwriting
-  // a filename to use as a enw file
-  let isBase = true
-  for (const dir of partialDirs) {
-    for (const f of fs.readdirSync(dir)) {
-      if (f.startsWith('_') || isBase) {
-        Handlebars.registerPartial(
-          partialName(f),
-          fs.readFileSync(join(dir, f)).toString()
-        )
-      }
-    }
-    isBase = false
+  makePartials(baseDir, true)
+  for (const dir of otherDirs) {
+    makePartials(dir)
   }
 }
 

test/apply/index.js

@@ -220,13 +220,16 @@ t.test('content can override partials', async (t) => {
     testdir: {
       content_dir: {
         '_step-deps.yml': '- run: INSTALL\n',
+        '_step-test.yml': '- run: TEST\n{{> defaultStepTest }}\n',
       },
     },
   })
   await s.apply()
   const ci = await s.readFile(join('.github', 'workflows', 'ci.yml'))
   t.ok(ci.includes('- run: INSTALL'))
+  t.ok(ci.includes('- run: TEST'))
   t.notOk(ci.includes('npm i --ignore-scripts --no-audit --no-fund'))
+  t.ok(ci.includes('npm test --ignore-scripts'))
 })
 
 t.test('content can extend files', async (t) => {