fix: set sourcemap root to the workspace relative root_dir (#176)

Author: jbedard

examples/filegroup/BUILD.bazel

@@ -5,6 +5,7 @@ filegroup(
     srcs = [
         "a.ts",
         "b.ts",
+        "sub/c.ts",
     ],
 )
 

examples/filegroup/check_outputs.sh

@@ -5,10 +5,15 @@ cd "$TEST_SRCDIR/$TEST_WORKSPACE/$(dirname $TEST_TARGET)"
 
 grep "export var a" filegroup/a.js
 grep "sourceMappingURL=a.js.map" filegroup/a.js
-grep --fixed-strings '"sourceRoot":"examples/filegroup"' filegroup/a.js.map
+grep --fixed-strings '"sourceRoot":""' filegroup/a.js.map
 grep --fixed-strings '"sources":["a.ts"]' filegroup/a.js.map
 
 grep "export var b" filegroup/b.js
 grep "sourceMappingURL=b.js.map" filegroup/b.js
-grep --fixed-strings '"sourceRoot":"examples/filegroup"' filegroup/b.js.map
-grep --fixed-strings '"sources":["b.ts"]' filegroup/b.js.map
+grep --fixed-strings '"sourceRoot":""' filegroup/b.js.map
+grep --fixed-strings '"sources":["b.ts"]' filegroup/b.js.map
+
+grep "export var c" filegroup/sub/c.js
+grep "sourceMappingURL=c.js.map" filegroup/sub/c.js
+grep --fixed-strings '"sourceRoot":""' filegroup/sub/c.js.map
+grep --fixed-strings '"sources":["c.ts"]' filegroup/sub/c.js.map

examples/filegroup/sub/c.ts

@@ -0,0 +1 @@
+export const c: string = "c";

examples/out_dir/BUILD.bazel

@@ -6,6 +6,7 @@ swc(
     srcs = [
         "a.ts",
         "b.ts",
+        "sub/c.ts",
     ],
     out_dir = "out",
     source_maps = True,
@@ -19,5 +20,7 @@ write_source_files(
         "expected/a.js.map": ":out/a.js.map",
         "expected/b.js": ":out/b.js",
         "expected/b.js.map": ":out/b.js.map",
+        "expected/sub/c.js": ":out/sub/c.js",
+        "expected/sub/c.js.map": ":out/sub/c.js.map",
     },
 )

examples/out_dir/expected/a.js.map

@@ -0,0 +1 @@
+export const c: string = "c";

examples/out_dir/expected/b.js.map

@@ -1,3 +1,6 @@
 {
-  "private": true
+  "private": true,
+  "dependencies": {
+    "source-map-support": "^0.5.21"
+  }
 }