fix: don't relativize paths to the swcrc location

maybe something changed upstream since that code was written?
The newly added example shows it working without that.

Fixes #11

examples/rc/.swcrc

@@ -0,0 +1,23 @@
+{
+    "jsc": {
+      "parser": {
+        "syntax": "typescript",
+        "tsx": false,
+        "decorators": true,
+        "dynamicImport": false
+      },
+      "transform": {
+        "legacyDecorator": true,
+        "decoratorMetadata": true
+      },
+      "target": "es2016"
+    },
+    "module": {
+      "type": "commonjs",
+      "strict": false,
+      "strictMode": true,
+      "lazy": false,
+      "noInterop": false
+    },
+    "sourceMaps": true
+  }

examples/rc/BUILD.bazel

@@ -0,0 +1 @@
+exports_files([".swcrc"])

examples/rc/src/BUILD.bazel

@@ -0,0 +1,24 @@
+load("@aspect_rules_swc//swc:swc.bzl", "swc")
+load("@bazel_skylib//rules:diff_test.bzl", "diff_test")
+
+# Runs `swc in.ts > ../../bazel-bin/examples/simple/in.js`
+# You can run `bazel build --subcommands //examples/simple:transpile`
+# to see the exact command line Bazel runs.
+# Note that by default, sources are found by glob(["**/*.ts"])
+swc(
+    name = "transpile",
+    source_maps = True,
+    swcrc = "//examples/rc:.swcrc",
+)
+
+diff_test(
+    name = "test",
+    file1 = "in.js",
+    file2 = "expected.js",
+)
+
+diff_test(
+    name = "test_map",
+    file1 = "in.js.map",
+    file2 = "expected.js.map",
+)

examples/rc/src/in.ts

@@ -0,0 +1 @@
+export const a: string = 'foo'

swc/private/swc.bzl

@@ -62,36 +62,32 @@ def _impl(ctx):
         outputs.extend(ctx.outputs.map_outs)
         for src in ctx.files.srcs:
             js_out = ctx.actions.declare_file(paths.replace_extension(src.basename, ".js"), sibling = src)
+            inputs = [src] + ctx.toolchains["@aspect_rules_swc//swc:toolchain_type"].swcinfo.tool_files
             outs = [js_out]
             if source_maps:
                 outs.append(ctx.actions.declare_file(paths.replace_extension(src.basename, ".js.map"), sibling = src))
 
-            # Pass in the swcrc config if it is set; if it is
-            # then source paths are expected to be relative to the swcrc directory
-            src_path = src.path
+            # Pass in the swcrc config if it is set
             if ctx.file.swcrc:
                 swcrc_path = ctx.file.swcrc.path
                 swcrc_directory = paths.dirname(swcrc_path)
                 args.add_all([
                     "--config-file",
                     swcrc_path,
                 ])
-
-                # TODO(greg): determine if this is needed, given that relativize below should provide a correct path
-                # if not src_path.startswith(swcrc_directory):
-                #     fail("sources must be in swcrc directory or subdirectory if swcrc is specified")
-                src_path = paths.relativize(src_path, swcrc_directory)
+                inputs.append(ctx.file.swcrc)
+            else:
+                args.add("--no-swcrc")
 
             args.add_all([
-                src_path,
+                src.path,
                 "--out-file",
                 js_out.path,
-                "--no-swcrc",
                 "-q",
             ])
 
             ctx.actions.run(
-                inputs = [src] + ctx.toolchains["@aspect_rules_swc//swc:toolchain_type"].swcinfo.tool_files,
+                inputs = inputs,
                 arguments = [args],
                 outputs = outs,
                 env = {