feat(replace): allow plugin to operate as an output plugin (#55)

* add execution hook to replace

* add tests to replacement

* break apart the executeReplacements function

* move sourcemap tests to separate module, test out different configurations

* fix(tests): correct sourcemaps test

* clean up eslint-disable directives

packages/replace/src/index.js

@@ -42,44 +42,57 @@ export default function replace(options = {}) {
   const keys = Object.keys(functionValues)
     .sort(longest)
     .map(escape);
-
   const pattern = delimiters
     ? new RegExp(`${escape(delimiters[0])}(${keys.join('|')})${escape(delimiters[1])}`, 'g')
     : new RegExp(`\\b(${keys.join('|')})\\b`, 'g');
 
   return {
     name: 'replace',
 
-    transform(code, id) {
+    renderChunk(code, chunk) {
+      const id = chunk.fileName;
       if (!keys.length) return null;
       if (!filter(id)) return null;
+      return executeReplacement(code, id);
+    },
 
-      const magicString = new MagicString(code);
-
-      let hasReplacements = false;
-      let match;
-      let start;
-      let end;
-      let replacement;
-
-      // eslint-disable-next-line no-cond-assign
-      while ((match = pattern.exec(code))) {
-        hasReplacements = true;
+    transform(code, id) {
+      if (!keys.length) return null;
+      if (!filter(id)) return null;
+      return executeReplacement(code, id);
+    }
+  };
 
-        start = match.index;
-        end = start + match[0].length;
-        replacement = String(functionValues[match[1]](id));
+  function executeReplacement(code, id) {
+    const magicString = new MagicString(code);
+    if (!codeHasReplacements(code, id, magicString)) {
+      return null;
+    }
 
-        magicString.overwrite(start, end, replacement);
-      }
+    const result = { code: magicString.toString() };
+    if (isSourceMapEnabled()) {
+      result.map = magicString.generateMap({ hires: true });
+    }
+    return result;
+  }
 
-      if (!hasReplacements) return null;
+  function codeHasReplacements(code, id, magicString) {
+    let result = false;
+    let match;
 
-      const result = { code: magicString.toString() };
-      if (options.sourceMap !== false && options.sourcemap !== false)
-        result.map = magicString.generateMap({ hires: true });
+    // eslint-disable-next-line no-cond-assign
+    while ((match = pattern.exec(code))) {
+      result = true;
 
-      return result;
+      const start = match.index;
+      const end = start + match[0].length;
+      const replacement = String(functionValues[match[1]](id));
+      magicString.overwrite(start, end, replacement);
     }
-  };
+    return result;
+  }
+
+  function isSourceMapEnabled() {
+    return options.sourceMap !== false && options.sourcemap !== false;
+  }
 }

packages/replace/test/misc.js

@@ -1,9 +1,7 @@
-/* eslint-disable consistent-return, global-require, import/no-dynamic-require */
+/* eslint-disable consistent-return */
 
 const test = require('ava');
 const { rollup } = require('rollup');
-const { SourceMapConsumer } = require('source-map');
-const { getLocator } = require('locate-character');
 
 const replace = require('../dist/rollup-plugin-replace.cjs.js');
 
@@ -33,78 +31,36 @@ test('does not mutate the values map properties', async (t) => {
   t.deepEqual(valuesMap, { ANSWER: '42' });
 });
 
-test('generates sourcemaps', async (t) => {
+test('can be configured with output plugins', async (t) => {
   const bundle = await rollup({
     input: 'main.js',
-    onwarn(warning) {
-      throw new Error(warning.message);
-    },
     plugins: [
-      replace({ values: { ANSWER: '42' } }),
       {
         resolveId(id) {
           return id;
         },
         load(importee) {
           if (importee === 'main.js') {
-            return 'import value from "other.js";\nlog(value);';
-          }
-          if (importee === 'other.js') {
-            return 'export default ANSWER;';
+            return 'log("environment", process.env.NODE_ENV);';
           }
         }
       }
     ]
   });
 
   const { code, map } = getOutputFromGenerated(
-    await bundle.generate({ format: 'es', sourcemap: true })
+    await bundle.generate({
+      format: 'es',
+      sourcemap: true,
+      plugins: [
+        replace({
+          'process.env.NODE_ENV': JSON.stringify('production'),
+          delimiters: ['', '']
+        })
+      ]
+    })
   );
 
-  await SourceMapConsumer.with(map, null, async (smc) => {
-    const locator = getLocator(code, { offsetLine: 1 });
-
-    let generatedLoc = locator('42');
-    let loc = smc.originalPositionFor(generatedLoc);
-    t.snapshot(generatedLoc);
-    t.snapshot(loc);
-
-    generatedLoc = locator('log');
-    loc = smc.originalPositionFor(generatedLoc);
-    t.snapshot(generatedLoc);
-    t.snapshot(loc);
-  });
-});
-
-test('does not generate sourcemaps if disabled', async (t) => {
-  let warned = false;
-
-  const bundle = await rollup({
-    input: 'main.js',
-    onwarn(warning) {
-      t.snapshot(warning.message);
-      warned = true;
-    },
-    plugins: [
-      replace({ values: { ANSWER: '42' }, sourcemap: false }),
-      {
-        resolveId(id) {
-          return id;
-        },
-
-        load(importee) {
-          if (importee === 'main.js') {
-            return 'import value from "other.js";\nlog(value);';
-          }
-          if (importee === 'other.js') {
-            return 'export default ANSWER;';
-          }
-        }
-      }
-    ]
-  });
-
-  t.truthy(!warned);
-  await bundle.generate({ format: 'es', sourcemap: true });
-  t.truthy(warned);
+  t.is(code.trim(), 'log("environment", "production");');
+  t.truthy(map);
 });

packages/replace/test/snapshots/sourcemaps.js.md

@@ -0,0 +1,185 @@
+# Snapshot report for `test/sourcemaps.js`
+
+The actual snapshot is saved in `sourcemaps.js.snap`.
+
+Generated by [AVA](https://ava.li).
+
+## generates sourcemaps when sourcemap is used as an output argument
+
+> Snapshot 1
+
+    {
+      character: 12,
+      column: 12,
+      line: 1,
+    }
+
+> Snapshot 2
+
+    {
+      column: 15,
+      line: 1,
+      name: null,
+      source: 'other.js',
+    }
+
+> Snapshot 3
+
+    {
+      character: 17,
+      column: 0,
+      line: 3,
+    }
+
+> Snapshot 4
+
+    {
+      column: 0,
+      line: 2,
+      name: null,
+      source: 'main.js',
+    }
+
+## generates sourcemaps if enabled in plugin
+
+> Snapshot 1
+
+    {
+      character: 12,
+      column: 12,
+      line: 1,
+    }
+
+> Snapshot 2
+
+    {
+      column: 15,
+      line: 1,
+      name: null,
+      source: 'other.js',
+    }
+
+> Snapshot 3
+
+    {
+      character: 17,
+      column: 0,
+      line: 3,
+    }
+
+> Snapshot 4
+
+    {
+      column: 0,
+      line: 2,
+      name: null,
+      source: 'main.js',
+    }
+
+## generates sourcemaps if enabled in plugin (camelcase)
+
+> Snapshot 1
+
+    {
+      character: 12,
+      column: 12,
+      line: 1,
+    }
+
+> Snapshot 2
+
+    {
+      column: 15,
+      line: 1,
+      name: null,
+      source: 'other.js',
+    }
+
+> Snapshot 3
+
+    {
+      character: 17,
+      column: 0,
+      line: 3,
+    }
+
+> Snapshot 4
+
+    {
+      column: 0,
+      line: 2,
+      name: null,
+      source: 'main.js',
+    }
+
+## generates sourcemaps by dfault
+
+> Snapshot 1
+
+    {
+      character: 12,
+      column: 12,
+      line: 1,
+    }
+
+> Snapshot 2
+
+    {
+      column: 15,
+      line: 1,
+      name: null,
+      source: 'other.js',
+    }
+
+> Snapshot 3
+
+    {
+      character: 17,
+      column: 0,
+      line: 3,
+    }
+
+> Snapshot 4
+
+    {
+      column: 0,
+      line: 2,
+      name: null,
+      source: 'main.js',
+    }
+
+## generates sourcemaps by default
+
+> Snapshot 1
+
+    {
+      character: 12,
+      column: 12,
+      line: 1,
+    }
+
+> Snapshot 2
+
+    {
+      column: 15,
+      line: 1,
+      name: null,
+      source: 'other.js',
+    }
+
+> Snapshot 3
+
+    {
+      character: 17,
+      column: 0,
+      line: 3,
+    }
+
+> Snapshot 4
+
+    {
+      column: 0,
+      line: 2,
+      name: null,
+      source: 'main.js',
+    }