fix decode, dont fix missing map.sources

src/compiler/preprocess/index.ts

@@ -103,7 +103,8 @@ function get_replacement(
 	let processed_map_shifted;
 	if (processed.map) {
 		const decoded_map = typeof processed.map === "string" ? JSON.parse(processed.map) : processed.map;
-		decoded_map.mappings = sourcemap_decode(decoded_map.mappings);
+		if (typeof(decoded_map.mappings) === 'string')
+			decoded_map.mappings = sourcemap_decode(decoded_map.mappings);
 		const processed_offset = get_location(offset + prefix.length);
 		processed_map_shifted = sourcemap_add_offset(decoded_map, processed_offset);
 	}
@@ -132,7 +133,7 @@ export default async function preprocess(
 	// sourcemap_list is sorted in reverse order from last map (index 0) to first map (index -1)
 	// so we use sourcemap_list.unshift() to add new maps
 	// https://github.com/ampproject/remapping#multiple-transformations-of-a-file
-	let sourcemap_list: Array<Processed['map']> = [];
+	const sourcemap_list: Array<Processed['map']> = [];
 
 	for (const fn of markup) {
 
@@ -215,14 +216,7 @@ export default async function preprocess(
 
 	// remapper can throw error
 	// `Transformation map ${i} must have exactly one source file.`
-	sourcemap_list = sourcemap_list
-		.map(sourcemap => {
-			if ((sourcemap as any).sources.filter(Boolean).length == 0)
-				// fix missing source file
-				(sourcemap as any).sources = [filename];
-			return sourcemap;
-		});
-
+	// for 0 <= i <= (sourcemap_list.length - 2)
 	const map: ReturnType<typeof remapper> =
 		sourcemap_list.length == 0
 			? null

test/sourcemaps/index.js

@@ -22,8 +22,10 @@ describe("sourcemaps", () => {
 		}
 
 		(solo ? it.only : skip ? it.skip : it)(dir, async () => {
+			const { test } = require(`./samples/${dir}/test.js`);
 			const inputFile = path.resolve(`${__dirname}/samples/${dir}/input.svelte`);
-			const outputBase = path.resolve(`${__dirname}/samples/${dir}/_actual`);
+			const outputName = '_actual';
+			const outputBase = path.resolve(`${__dirname}/samples/${dir}/${outputName}`);
 
 			const input = {};
 			input.code = fs.readFileSync(inputFile, "utf-8");
@@ -37,11 +39,9 @@ describe("sourcemaps", () => {
 					filename: "input.svelte"
 				});
 			} catch (error) {
-				preprocessed = {
-					error,
-					code: '',
-					map: null
-				};
+				preprocessed = { error };
+				// run test without js, css
+				return test({ assert, input, preprocessed });
 			}
 
 			const { js, css } = svelte.compile(
@@ -49,8 +49,8 @@ describe("sourcemaps", () => {
 				filename: "input.svelte",
 				sourcemap: preprocessed.map,
 				// filenames for sourcemaps
-				outputFilename: "output.js",
-				cssOutputFilename: "output.css",
+				outputFilename: `${outputName}.js`,
+				cssOutputFilename: `${outputName}.css`,
 			});
 
 			js.code = js.code.replace(
@@ -64,7 +64,7 @@ describe("sourcemaps", () => {
 			}
 			fs.writeFileSync(
 				`${outputBase}.js`,
-				`${js.code}\n//# sourceMappingURL=output.js.map`
+				`${js.code}\n//# sourceMappingURL=${outputName}.js.map`
 			);
 			fs.writeFileSync(
 				`${outputBase}.js.map`,
@@ -73,7 +73,7 @@ describe("sourcemaps", () => {
 			if (css.code) {
 				fs.writeFileSync(
 					`${outputBase}.css`,
-					`${css.code}\n/*# sourceMappingURL=output.css.map */`
+					`${css.code}\n/*# sourceMappingURL=${outputName}.css.map */`
 				);
 				fs.writeFileSync(
 					`${outputBase}.css.map`,
@@ -84,8 +84,6 @@ describe("sourcemaps", () => {
 			assert.deepEqual(js.map.sources, ["input.svelte"]);
 			if (css.map) assert.deepEqual(css.map.sources, ["input.svelte"]);
 
-			const { test } = require(`./samples/${dir}/test.js`);
-
 			preprocessed.mapConsumer = preprocessed.map && await new SourceMapConsumer(preprocessed.map);
 			preprocessed.locate = getLocator(preprocessed.code);
 
@@ -96,7 +94,6 @@ describe("sourcemaps", () => {
 			css.locate = getLocator(css.code || "");
 
 			test({ assert, input, preprocessed, js, css });
-
 		});
 	});
 });

test/sourcemaps/samples/sourcemap-names/test.js

@@ -8,6 +8,7 @@ export function test({ assert, input, preprocessed, js, css }) {
 		['baritone', '--bazitone', 'old_name_1', 'old_name_2'].sort()
 	);
 
+  // TODO move fn test_name to test/sourcemaps/index.js and use in samples/*/test.js
 	function test_name(old_name, new_name, where) {
 
 		let loc = { character: -1 };

test/sourcemaps/samples/sourcemap-sources/_config.js

@@ -1,21 +1,26 @@
 import MagicString from 'magic-string';
+// eslint warning: import/no-named-as-default-member
+
+//import MagicString, { Bundle } from 'magic-string';
+// TODO why does this break mocha?
+// SyntaxError: Cannot use import statement outside a module
 
 function add(bundle, filename, source) {
-  bundle.addSource({
-    filename: filename,
-    content: new MagicString(source)
-  });
+	bundle.addSource({
+		filename,
+		content: new MagicString(source)
+	});
 }
 
 function result(bundle, filename) {
-  return {
-    code: bundle.toString(),
-    map: bundle.generateMap({
-      file: filename,
-      includeContent: true,
-      hires: true
-    })
-  };
+	return {
+		code: bundle.toString(),
+		map: bundle.generateMap({
+			file: filename,
+			includeContent: true,
+			hires: true
+		})
+	};
 }
 
 export default {
@@ -28,7 +33,7 @@ export default {
 				add(bundle, 'foo.js', 'var answer = 42;');
 				add(bundle, 'bar.js', 'console.log(answer);');
 
-        return result(bundle, filename);
+				return result(bundle, filename);
 			}
 		},
 		{
@@ -39,7 +44,7 @@ export default {
 				add(bundle, 'foo2.js', 'var answer2 = 84;');
 				add(bundle, 'bar2.js', 'console.log(answer2);');
 
-        return result(bundle, filename);
+				return result(bundle, filename);
 			}
 		}
 	]