Inline single export from current source (#259)

kristoferbaxter · web-flow · commit 2731853ce1d3 · 2019-12-23T21:48:12.000-08:00
* Partial support for inlining single export from current source
* Fix remainder of tests
diff --git a/src/options.ts b/src/options.ts
@@ -23,14 +23,14 @@ import { log, logSource } from './debug';
 export const ERROR_WARNINGS_ENABLED_LANGUAGE_OUT_UNSPECIFIED =
   'Providing the warning_level=VERBOSE compile option also requires a valid language_out compile option.';
 export const ERROR_WARNINGS_ENABLED_LANGUAGE_OUT_INVALID =
-  'Providing the warning_level=VERBOSE and language_out=NO_TRANSPILE compile option will remove warnings.';
+  'Providing the warning_level=VERBOSE and language_out=NO_TRANSPILE compile options will remove warnings.';
 
 /**
  * Checks if output format is ESM
  * @param format
  * @return boolean
  */
-export const isESMFormat = (format?: ModuleFormat | 'esm'): boolean => {
+export const isESMFormat = (format?: ModuleFormat): boolean => {
   // TODO: remove `| 'esm'` when rollup upgrades its typings
   return format === 'esm' || format === 'es';
 };
@@ -64,10 +64,8 @@ export const defaults = (
   // Defaults for Rollup Projects are slightly different than Closure Compiler defaults.
   // - Users of Rollup tend to transpile their code before handing it to a minifier,
   // so no transpile is default.
-  // - When Rollup output is set to "es" it is expected the code will live in a ES Module,
+  // - When Rollup output is set to "es|esm" it is expected the code will live in a ES Module,
   // so safely be more aggressive in minification.
-  // - When Rollup is configured to output an iife, ensure Closure Compiler does not
-  // mangle the name of the iife wrapper.
 
   const externs = transformers
     ? transformers
@@ -139,5 +137,7 @@ export default function(
     create_source_map: mapFile,
   };
 
+  log('compile options', options);
+
   return [options, mapFile];
 }
diff --git a/src/transformers/exports.ts b/src/transformers/exports.ts
@@ -51,13 +51,19 @@ var exports;`;
 export default class ExportTransform extends Transform implements TransformInterface {
   public name = 'ExportTransform';
   private originalExports: Map<string, ExportDetails> = new Map();
+  private currentSourceExportCount: number = 0;
 
   /**
    * Store an export from a source into the originalExports Map.
    * @param mapping mapping of details from this declaration.
    */
   private storeExport = (mapping: Array<ExportDetails>): void =>
-    mapping.forEach(map => this.originalExports.set(map.closureName, map));
+    mapping.forEach(map => {
+      if (map.source === null) {
+        this.currentSourceExportCount++;
+      }
+      this.originalExports.set(map.closureName, map);
+    });
 
   private static storeExportToAppend(
     collected: Map<string | null, Array<string>>,
@@ -173,7 +179,7 @@ export default class ExportTransform extends Transform implements TransformInter
       const source = new MagicString(code);
       const program = parse(code);
       let collectedExportsToAppend: Map<string | null, Array<string>> = new Map();
-      const { originalExports } = this;
+      const { originalExports, currentSourceExportCount } = this;
 
       source.trimEnd();
 
@@ -218,10 +224,17 @@ export default class ExportTransform extends Transform implements TransformInter
                       }
                       break;
                     case ExportClosureMapping.NAMED_CONSTANT:
-                      if (exportDetails.source === null) {
+                      const exportFromCurrentSource = exportDetails.source === null;
+                      const inlineExport =
+                        exportFromCurrentSource && currentSourceExportCount === 1;
+                      // KRIS YOU'RE HERE!
+                      // When there is only a single export from the current source (source=null)
+                      // then inline the export statement instead of sending it into the collection for appending.
+                      if (exportFromCurrentSource) {
                         const { object: leftObject } = ancestor.expression.left;
                         if (leftObject.range) {
-                          source.overwrite(leftObject.range[0], leftObject.range[1] + 1, 'var ');
+                          const statement = inlineExport ? 'export var ' : 'var ';
+                          source.overwrite(leftObject.range[0], leftObject.range[1] + 1, statement);
                         }
                         if (exportDetails.local !== exportDetails.exported) {
                           exportDetails.local = exportDetails.exported;
@@ -237,10 +250,12 @@ export default class ExportTransform extends Transform implements TransformInter
                         );
                       }
 
-                      collectedExportsToAppend = ExportTransform.storeExportToAppend(
-                        collectedExportsToAppend,
-                        exportDetails,
-                      );
+                      if (!inlineExport) {
+                        collectedExportsToAppend = ExportTransform.storeExportToAppend(
+                          collectedExportsToAppend,
+                          exportDetails,
+                        );
+                      }
                       break;
                   }
                 }
diff --git a/test/arrow-function/fixtures/multiple-arguments.esm.advanced.js b/test/arrow-function/fixtures/multiple-arguments.esm.advanced.js
@@ -1 +1 @@
-var multipleArguments=(a,b)=>console.log(a,b);export{multipleArguments};
+export var multipleArguments=(a,b)=>console.log(a,b);
diff --git a/test/arrow-function/fixtures/multiple-arguments.esm.default.js b/test/arrow-function/fixtures/multiple-arguments.esm.default.js
@@ -1 +1 @@
-var multipleArguments=(a,b)=>console.log(a,b);export{multipleArguments};
+export var multipleArguments=(a,b)=>console.log(a,b);
diff --git a/test/arrow-function/fixtures/multiple-arguments.esm.es5.js b/test/arrow-function/fixtures/multiple-arguments.esm.es5.js
@@ -1 +1 @@
-var multipleArguments=function(a,b){return console.log(a,b)};export{multipleArguments};
+export var multipleArguments=function(a,b){return console.log(a,b)};
diff --git a/test/arrow-function/fixtures/single-argument.esm.advanced.js b/test/arrow-function/fixtures/single-argument.esm.advanced.js
@@ -1 +1 @@
-var singleArgument=a=>console.log(a);export{singleArgument};
+export var singleArgument=a=>console.log(a);
diff --git a/test/arrow-function/fixtures/single-argument.esm.default.js b/test/arrow-function/fixtures/single-argument.esm.default.js
@@ -1 +1 @@
-var singleArgument=a=>console.log(a);export{singleArgument};
+export var singleArgument=a=>console.log(a);
diff --git a/test/arrow-function/fixtures/single-argument.esm.es5.js b/test/arrow-function/fixtures/single-argument.esm.es5.js
@@ -1 +1 @@
-var singleArgument=function(a){return console.log(a)};export{singleArgument};
+export var singleArgument=function(a){return console.log(a)};
diff --git a/test/const-rename/fixtures/rename.esm.advanced.js b/test/const-rename/fixtures/rename.esm.advanced.js
@@ -1 +1 @@
-let b=[3,4],c=[5,6];var yes=function(a){return 0<=c.indexOf(a)&&0<=b.indexOf(a)};export{yes};
+let b=[3,4],c=[5,6];export var yes=function(a){return 0<=c.indexOf(a)&&0<=b.indexOf(a)};
diff --git a/test/const-rename/fixtures/rename.esm.default.js b/test/const-rename/fixtures/rename.esm.default.js
@@ -1 +1 @@
-let b=[3,4],c=[5,6];var yes=function(a){return 0<=c.indexOf(a)&&0<=b.indexOf(a)};export{yes};
+let b=[3,4],c=[5,6];export var yes=function(a){return 0<=c.indexOf(a)&&0<=b.indexOf(a)};
diff --git a/test/const-rename/fixtures/rename.esm.es5.js b/test/const-rename/fixtures/rename.esm.es5.js
@@ -1 +1 @@
-var b=[3,4],c=[5,6];var yes=function(a){return 0<=c.indexOf(a)&&0<=b.indexOf(a)};export{yes};
+var b=[3,4],c=[5,6];export var yes=function(a){return 0<=c.indexOf(a)&&0<=b.indexOf(a)};
diff --git a/test/export-named/fixtures/identifier-alias.esm.advanced.js b/test/export-named/fixtures/identifier-alias.esm.advanced.js
@@ -1 +1 @@
-var bar=1;export{bar};
+export var bar=1;
diff --git a/test/export-named/fixtures/identifier-alias.esm.default.js b/test/export-named/fixtures/identifier-alias.esm.default.js
@@ -1 +1 @@
-var bar=1;export{bar};
+export var bar=1;
diff --git a/test/export-named/fixtures/identifier-alias.esm.es5.js b/test/export-named/fixtures/identifier-alias.esm.es5.js
@@ -1 +1 @@
-var bar=1;export{bar};
+export var bar=1;
diff --git a/test/export-named/fixtures/identifier.esm.advanced.js b/test/export-named/fixtures/identifier.esm.advanced.js
@@ -1 +1 @@
-var foo=1;export{foo};
+export var foo=1;
diff --git a/test/export-named/fixtures/identifier.esm.default.js b/test/export-named/fixtures/identifier.esm.default.js
@@ -1 +1 @@
-var foo=1;export{foo};
+export var foo=1;
diff --git a/test/export-named/fixtures/identifier.esm.es5.js b/test/export-named/fixtures/identifier.esm.es5.js
@@ -1 +1 @@
-var foo=1;export{foo};
+export var foo=1;
diff --git a/test/export-transpilation/fixtures/named-constant.esm.advanced.js b/test/export-transpilation/fixtures/named-constant.esm.advanced.js
@@ -1 +1 @@
-var b=Symbol.for("smth");var isSmth=a=>a&&!!a[b];export{isSmth};
+var b=Symbol.for("smth");export var isSmth=a=>a&&!!a[b];
diff --git a/test/export-transpilation/fixtures/named-constant.esm.default.js b/test/export-transpilation/fixtures/named-constant.esm.default.js
@@ -1 +1 @@
-var b=Symbol.for("smth");var isSmth=a=>a&&!!a[b];export{isSmth};
+var b=Symbol.for("smth");export var isSmth=a=>a&&!!a[b];
diff --git a/test/export-transpilation/fixtures/named-constant.esm.es5.js b/test/export-transpilation/fixtures/named-constant.esm.es5.js
diff --git a/test/export-transpilation/fixtures/named-function.esm.advanced.js b/test/export-transpilation/fixtures/named-function.esm.advanced.js
@@ -1 +1 @@
-var b=Symbol.for("smth");var isSmth=function(a){return a&&!!a[b]};export{isSmth};
+var b=Symbol.for("smth");export var isSmth=function(a){return a&&!!a[b]};
diff --git a/test/export-transpilation/fixtures/named-function.esm.default.js b/test/export-transpilation/fixtures/named-function.esm.default.js
@@ -1 +1 @@
-var b=Symbol.for("smth");var isSmth=function(a){return a&&!!a[b]};export{isSmth};
+var b=Symbol.for("smth");export var isSmth=function(a){return a&&!!a[b]};
diff --git a/test/export-transpilation/fixtures/named-function.esm.es5.js b/test/export-transpilation/fixtures/named-function.esm.es5.js
@@ -1 +1 @@
-var b=Symbol.for("smth");var isSmth=function(a){return a&&!!a[b]};export{isSmth};
+var b=Symbol.for("smth");export var isSmth=function(a){return a&&!!a[b]};
diff --git a/test/export-variables/fixtures/class.esm.advanced.js b/test/export-variables/fixtures/class.esm.advanced.js
@@ -1 +1 @@
-class a{constructor(b){this.a=b}console(){console.log(this.a)}}var Exported=a;export{Exported};
+class a{constructor(b){this.a=b}console(){console.log(this.a)}}export var Exported=a;
diff --git a/test/export-variables/fixtures/class.esm.default.js b/test/export-variables/fixtures/class.esm.default.js
@@ -1 +1 @@
-class a{constructor(b){this.name_=b}console(){console.log(this.name_)}}var Exported=a;export{Exported};
+class a{constructor(b){this.name_=b}console(){console.log(this.name_)}}export var Exported=a;
diff --git a/test/export-variables/fixtures/class.esm.es5.js b/test/export-variables/fixtures/class.esm.es5.js
@@ -1 +1 @@
-function a(b){this.name_=b}a.prototype.console=function(){console.log(this.name_)};var Exported=a;export{Exported};
+function a(b){this.name_=b}a.prototype.console=function(){console.log(this.name_)};export var Exported=a;
diff --git a/test/export-variables/fixtures/const-function.esm.advanced.js b/test/export-variables/fixtures/const-function.esm.advanced.js
@@ -1 +1 @@
-var foo=function(a){console.log(a)};export{foo};
+export var foo=function(a){console.log(a)};
diff --git a/test/export-variables/fixtures/const-function.esm.default.js b/test/export-variables/fixtures/const-function.esm.default.js
@@ -1 +1 @@
-var foo=function(a){console.log(a)};export{foo};
+export var foo=function(a){console.log(a)};
diff --git a/test/export-variables/fixtures/const-function.esm.es5.js b/test/export-variables/fixtures/const-function.esm.es5.js
@@ -1 +1 @@
-var foo=function(a){console.log(a)};export{foo};
+export var foo=function(a){console.log(a)};
diff --git a/test/export-variables/fixtures/const-number.esm.advanced.js b/test/export-variables/fixtures/const-number.esm.advanced.js
@@ -1 +1 @@
-var foo=1;export{foo};
+export var foo=1;
diff --git a/test/export-variables/fixtures/const-number.esm.default.js b/test/export-variables/fixtures/const-number.esm.default.js
@@ -1 +1 @@
-var foo=1;export{foo};
+export var foo=1;
diff --git a/test/export-variables/fixtures/const-number.esm.es5.js b/test/export-variables/fixtures/const-number.esm.es5.js
@@ -1 +1 @@
-var foo=1;export{foo};
+export var foo=1;
diff --git a/test/export-variables/fixtures/function.esm.advanced.js b/test/export-variables/fixtures/function.esm.advanced.js
@@ -1 +1 @@
-var foo=function(a){console.log(a)};export{foo};
+export var foo=function(a){console.log(a)};
diff --git a/test/export-variables/fixtures/function.esm.default.js b/test/export-variables/fixtures/function.esm.default.js
@@ -1 +1 @@
-var foo=function(a){console.log(a)};export{foo};
+export var foo=function(a){console.log(a)};
diff --git a/test/export-variables/fixtures/function.esm.es5.js b/test/export-variables/fixtures/function.esm.es5.js
@@ -1 +1 @@
-var foo=function(a){console.log(a)};export{foo};
+export var foo=function(a){console.log(a)};
diff --git a/test/export-variables/fixtures/let-function.esm.advanced.js b/test/export-variables/fixtures/let-function.esm.advanced.js
@@ -1 +1 @@
-var foo=function(a){console.log(a)};export{foo};
+export var foo=function(a){console.log(a)};
diff --git a/test/export-variables/fixtures/let-function.esm.default.js b/test/export-variables/fixtures/let-function.esm.default.js
@@ -1 +1 @@
-var foo=function(a){console.log(a)};export{foo};
+export var foo=function(a){console.log(a)};
diff --git a/test/export-variables/fixtures/let-function.esm.es5.js b/test/export-variables/fixtures/let-function.esm.es5.js
@@ -1 +1 @@
-var foo=function(a){console.log(a)};export{foo};
+export var foo=function(a){console.log(a)};
diff --git a/test/export-variables/fixtures/let-identifier.esm.advanced.js b/test/export-variables/fixtures/let-identifier.esm.advanced.js
@@ -1 +1 @@
-var foo=1;export{foo};
+export var foo=1;
diff --git a/test/export-variables/fixtures/let-identifier.esm.default.js b/test/export-variables/fixtures/let-identifier.esm.default.js
@@ -1 +1 @@
-var foo=1;export{foo};
+export var foo=1;
diff --git a/test/export-variables/fixtures/let-identifier.esm.es5.js b/test/export-variables/fixtures/let-identifier.esm.es5.js
@@ -1 +1 @@
-var foo=1;export{foo};
+export var foo=1;
diff --git a/test/export-variables/fixtures/let-number.esm.advanced.js b/test/export-variables/fixtures/let-number.esm.advanced.js
@@ -1 +1 @@
-var foo=1;export{foo};
+export var foo=1;
diff --git a/test/export-variables/fixtures/let-number.esm.default.js b/test/export-variables/fixtures/let-number.esm.default.js
@@ -1 +1 @@
-var foo=1;export{foo};
+export var foo=1;
diff --git a/test/export-variables/fixtures/let-number.esm.es5.js b/test/export-variables/fixtures/let-number.esm.es5.js
@@ -1 +1 @@
-var foo=1;export{foo};
+export var foo=1;
diff --git a/test/export-variables/fixtures/var-function.esm.advanced.js b/test/export-variables/fixtures/var-function.esm.advanced.js
@@ -1 +1 @@
-var foo=function(a){console.log(a)};export{foo};
+export var foo=function(a){console.log(a)};
diff --git a/test/export-variables/fixtures/var-function.esm.default.js b/test/export-variables/fixtures/var-function.esm.default.js
@@ -1 +1 @@
-var foo=function(a){console.log(a)};export{foo};
+export var foo=function(a){console.log(a)};
diff --git a/test/export-variables/fixtures/var-function.esm.es5.js b/test/export-variables/fixtures/var-function.esm.es5.js
@@ -1 +1 @@
-var foo=function(a){console.log(a)};export{foo};
+export var foo=function(a){console.log(a)};
diff --git a/test/export-variables/fixtures/var-identifier.esm.advanced.js b/test/export-variables/fixtures/var-identifier.esm.advanced.js
@@ -1 +1 @@
-var foo=1;export{foo};
+export var foo=1;
diff --git a/test/export-variables/fixtures/var-identifier.esm.default.js b/test/export-variables/fixtures/var-identifier.esm.default.js
@@ -1 +1 @@
-var foo=1;export{foo};
+export var foo=1;
diff --git a/test/export-variables/fixtures/var-identifier.esm.es5.js b/test/export-variables/fixtures/var-identifier.esm.es5.js
@@ -1 +1 @@
-var foo=1;export{foo};
+export var foo=1;
diff --git a/test/export-variables/fixtures/var-number.esm.advanced.js b/test/export-variables/fixtures/var-number.esm.advanced.js
@@ -1 +1 @@
-var foo=1;export{foo};
+export var foo=1;
diff --git a/test/export-variables/fixtures/var-number.esm.default.js b/test/export-variables/fixtures/var-number.esm.default.js
@@ -1 +1 @@
-var foo=1;export{foo};
+export var foo=1;
diff --git a/test/export-variables/fixtures/var-number.esm.es5.js b/test/export-variables/fixtures/var-number.esm.es5.js
@@ -1 +1 @@
-var foo=1;export{foo};
+export var foo=1;
diff --git a/test/import/fixtures/dynamic-imported-67216f69.esm.default.js b/test/import/fixtures/dynamic-imported-67216f69.esm.default.js
@@ -1 +1 @@
-var handleImport=function(){return 2};export{handleImport};
+export var handleImport=function(){return 2};
diff --git a/test/import/fixtures/dynamic-imported-67216f69.esm.es5.js b/test/import/fixtures/dynamic-imported-67216f69.esm.es5.js
@@ -1 +1 @@
-var handleImport=function(){return 2};export{handleImport};
+export var handleImport=function(){return 2};
diff --git a/test/import/fixtures/dynamic-imported.esm.advanced.js b/test/import/fixtures/dynamic-imported.esm.advanced.js
@@ -1 +1 @@
-var handleImport=function(){return 2};export{handleImport};
+export var handleImport=function(){return 2};
diff --git a/test/import/fixtures/dynamic.esm.advanced.js b/test/import/fixtures/dynamic.esm.advanced.js
@@ -1 +1 @@
-var exported=function(){import("./dynamic-imported-67216f69.js").then((a)=>a.handleImport())};export{exported};
+export var exported=function(){import("./dynamic-imported-67216f69.js").then((a)=>a.handleImport())};
diff --git a/test/import/fixtures/dynamic.esm.default.js b/test/import/fixtures/dynamic.esm.default.js
@@ -1 +1 @@
-var exported=function(){import("./dynamic-imported-67216f69.js").then(a=>a.handleImport())};export{exported};
+export var exported=function(){import("./dynamic-imported-67216f69.js").then(a=>a.handleImport())};
diff --git a/test/import/fixtures/dynamic.esm.es5.js b/test/import/fixtures/dynamic.esm.es5.js
@@ -1 +1 @@
-var exported=function(){import("./dynamic-imported-67216f69.js").then(function(a){return a.handleImport()})};export{exported};
+export var exported=function(){import("./dynamic-imported-67216f69.js").then(function(a){return a.handleImport()})};
diff --git a/test/import/fixtures/flattened.esm.advanced.js b/test/import/fixtures/flattened.esm.advanced.js
@@ -1 +1 @@
-var exported=function(a){console.log(a);console.log(1)};export{exported};
+export var exported=function(a){console.log(a);console.log(1)};
diff --git a/test/import/fixtures/flattened.esm.default.js b/test/import/fixtures/flattened.esm.default.js
@@ -1 +1 @@
-var exported=function(a){console.log(a);console.log(1)};export{exported};
+export var exported=function(a){console.log(a);console.log(1)};
diff --git a/test/import/fixtures/flattened.esm.es5.js b/test/import/fixtures/flattened.esm.es5.js
@@ -1 +1 @@
-var exported=function(a){console.log(a);console.log(1)};export{exported};
+export var exported=function(a){console.log(a);console.log(1)};
diff --git a/test/provided-externs/fixtures/class.esm.advanced.js b/test/provided-externs/fixtures/class.esm.advanced.js
@@ -1 +1 @@
-class a{constructor(b){this.a=b}console(){console.log(this.a)}}var ExportThis=a;export{ExportThis};
+class a{constructor(b){this.a=b}console(){console.log(this.a)}}export var ExportThis=a;
diff --git a/test/provided-externs/fixtures/class.esm.default.js b/test/provided-externs/fixtures/class.esm.default.js
@@ -1 +1 @@
-class a{constructor(b){this.name_=b}console(){console.log(this.name_)}}var ExportThis=a;export{ExportThis};
+class a{constructor(b){this.name_=b}console(){console.log(this.name_)}}export var ExportThis=a;
diff --git a/test/provided-externs/fixtures/class.esm.es5.js b/test/provided-externs/fixtures/class.esm.es5.js
@@ -1 +1 @@
-function a(b){this.name_=b}a.prototype.console=function(){console.log(this.name_)};var ExportThis=a;export{ExportThis};
+function a(b){this.name_=b}a.prototype.console=function(){console.log(this.name_)};export var ExportThis=a;

Original file line number	Diff line number	Diff line change
`@@ -1 +1 @@`
`1`		`-var multipleArguments=(a,b)=>console.log(a,b);export{multipleArguments};`
	`1`	`+export var multipleArguments=(a,b)=>console.log(a,b);`
Original file line number	Diff line number	Diff line change
`@@ -1 +1 @@`
`1`		`-var multipleArguments=function(a,b){return console.log(a,b)};export{multipleArguments};`
	`1`	`+export var multipleArguments=function(a,b){return console.log(a,b)};`
Original file line number	Diff line number	Diff line change
`@@ -1 +1 @@`
`1`		`-var singleArgument=a=>console.log(a);export{singleArgument};`
	`1`	`+export var singleArgument=a=>console.log(a);`
Original file line number	Diff line number	Diff line change
`@@ -1 +1 @@`
`1`		`-var singleArgument=function(a){return console.log(a)};export{singleArgument};`
	`1`	`+export var singleArgument=function(a){return console.log(a)};`
Original file line number	Diff line number	Diff line change
`@@ -1 +1 @@`
`1`		`-let b=[3,4],c=[5,6];var yes=function(a){return 0<=c.indexOf(a)&&0<=b.indexOf(a)};export{yes};`
	`1`	`+let b=[3,4],c=[5,6];export var yes=function(a){return 0<=c.indexOf(a)&&0<=b.indexOf(a)};`