Fix compressed source-maps have non-terminated segments

lib/sourcemap.js

@@ -82,12 +82,20 @@ async function SourceMap(options) {
     }
 
     function add(source, gen_line, gen_col, orig_line, orig_col, name) {
+        let generatedPos = { line: gen_line, column: gen_col };
+
         if (orig_map) {
             var info = orig_map.originalPositionFor({
                 line: orig_line,
                 column: orig_col
             });
             if (info.source === null) {
+                generator.addMapping({
+                    generated: generatedPos,
+                    original: null,
+                    source: null,
+                    name: null
+                });
                 return;
             }
             source = info.source;
@@ -96,7 +104,7 @@ async function SourceMap(options) {
             name = info.name || name;
         }
         generator.addMapping({
-            generated : { line: gen_line, column: gen_col },
+            generated : generatedPos,
             original  : { line: orig_line, column: orig_col },
             source    : source,
             name      : name

test/input/source-maps/input.js

@@ -1,11 +1,17 @@
-function _toConsumableArray(arr) { if (Array.isArray(arr)) { for (var i = 0, arr2 = Array(arr.length); i < arr.length; i++) { arr2[i] = arr[i]; } return arr2; } else { return Array.from(arr); } }
-
-var _require = require("bar"),
-    foo = _require.foo;
-
-var _require2 = require("world"),
-    hello = _require2.hello;
-
-foo.x.apply(foo, _toConsumableArray(foo.y(hello.z)));
-
-//# sourceMappingURL=input.js.map
+"use strict";
+var __awaiter = (this && this.__awaiter) || function (thisArg, _arguments, P, generator) {
+    function adopt(value) { return value instanceof P ? value : new P(function (resolve) { resolve(value); }); }
+    return new (P || (P = Promise))(function (resolve, reject) {
+        function fulfilled(value) { try { step(generator.next(value)); } catch (e) { reject(e); } }
+        function rejected(value) { try { step(generator["throw"](value)); } catch (e) { reject(e); } }
+        function step(result) { result.done ? resolve(result.value) : adopt(result.value).then(fulfilled, rejected); }
+        step((generator = generator.apply(thisArg, _arguments || [])).next());
+    });
+};
+function somePromiseFn() {
+    return __awaiter(this, void 0, void 0, function* () {
+        let value = 'promise-value';
+        return value;
+    });
+}
+somePromiseFn().then(d => console.info(d));

test/mocha/input-sourcemaps.js

@@ -2,7 +2,7 @@ import assert from "assert";
 import { minify } from "../../main.js";
 import source_map from "source-map"
 
-const { SourceMapConsumer } = source_map
+const { SourceMapConsumer, SourceMapGenerator } = source_map
 
 describe("input sourcemaps", function() {
     var transpilemap, map;
@@ -65,4 +65,52 @@ describe("input sourcemaps", function() {
             assert.ok(pos.line <= 2, msg);
         })
     });
+
+    it("Should preserve unmapped segments in output source map", async function() {
+        var generator = new SourceMapGenerator();
+
+        generator.addMapping({
+            source: "source.ts",
+            generated: {line: 1, column: 0},
+            original: {line: 1, column: 0},
+        });
+        generator.addMapping({
+            source: null,
+            generated: {line: 1, column: 37},
+            original: null,
+        });
+
+        generator.addMapping({
+            source: "source.ts",
+            generated: {line: 1, column: 50},
+            original: {line: 2, column: 0},
+        });
+
+        generator.setSourceContent("source.ts",
+            `function say(msg) {console.log(msg)};say('hello');\nprocess.exit(1);`)
+
+        // Everything except the "say('hello');" part is mapped to "source.ts". The "say"
+        // function call is not mapped to any original source location. e.g. this can
+        // happen when a code transformer inserts generated code in between existing code.
+        var inputFile = "function say(msg) {console.log(msg)};say('hello');process.exit(1);";
+        var result = await minify(inputFile, {
+            sourceMap: {
+                content: JSON.parse(generator.toString()),
+                url: 'inline'
+            }
+        });
+
+        var transformedMap = await new SourceMapConsumer(result.map);
+        var hasMappedSource = true;
+
+        for (let i = 0; i < result.code.length; i++) {
+            var info = transformedMap.originalPositionFor({line: 1, column: i});
+            hasMappedSource = hasMappedSource && !!info.source;
+        }
+
+        assert.equal(hasMappedSource, false, "Expected transformed source map to preserve the " +
+            "mapping without original source location");
+
+        assert.doesNotThrow(() => SourceMapGenerator.fromSourceMap(transformedMap));
+    });
 });