fix(esbuild): add link_workspace_root for workspace absolute imports

Fixes bazel-contrib#2474

packages/esbuild/esbuild.bzl

@@ -15,6 +15,9 @@ def _esbuild_impl(ctx):
     # how to resolve custom package or module names
     path_alias_mappings = dict()
 
+    if (ctx.attr.link_workspace_root):
+        path_alias_mappings.update(generate_path_mapping(ctx.workspace_name, "/".join(ctx.build_file_path.split("/")[:-1])))
+
     for dep in ctx.attr.deps:
         if JSEcmaScriptModuleInfo in dep:
             deps_depsets.append(dep[JSEcmaScriptModuleInfo].sources)
@@ -152,6 +155,10 @@ and cjs when platform is node. If performing code splitting, defaults to esm.
 
 See https://esbuild.github.io/api/#format for more details
         """,
+        ),
+        "link_workspace_root": attr.bool(
+            doc = """Link the workspace root to the bin_dir to support absolute requires like 'my_wksp/path/to/file'.
+    If source files need to be required then they can be copied to the bin_dir with copy_to_bin.""",
         ),
         "minify": attr.bool(
             default = False,

packages/esbuild/test/workspace-mapping/BUILD.bazel

@@ -0,0 +1,30 @@
+load("//:index.bzl", "generated_file_test")
+load("//packages/esbuild/test:tests.bzl", "esbuild")
+
+esbuild(
+    name = "bundle",
+    entry_point = "main.js",
+    format = "esm",
+    link_workspace_root = True,
+    deps = [
+        "//packages/esbuild/test/workspace-mapping/module-one",
+        "//packages/esbuild/test/workspace-mapping/module-two",
+    ],
+)
+
+# esbuild will put the filepath in a comment within the non-minified file,
+# on different platforms this will cause the golden test to differ
+# strip them here
+# note that this regex doesn't strip the sourcemap URI comment
+genrule(
+    name = "strip_bundle_comments",
+    srcs = ["bundle.js"],
+    outs = ["bundle.stripped.js"],
+    cmd = "cat $(location :bundle.js) | sed \"s#// .*##\" > $@",
+)
+
+generated_file_test(
+    name = "bundle_test",
+    src = "bundle.golden.txt",
+    generated = "bundle.stripped.js",
+)

packages/esbuild/test/workspace-mapping/bundle.golden.txt

@@ -0,0 +1,15 @@
+var __defProp = Object.defineProperty;
+var __name = (target, value) => __defProp(target, "name", {value, configurable: true});
+
+
+var getId = /* @__PURE__ */ __name(() => "module-one", "getId");
+
+
+var getId2 = /* @__PURE__ */ __name(() => "module-two", "getId");
+
+
+var main_default = `Full ID: ${getId} - ${getId2}`;
+export {
+  main_default as default
+};
+//# sourceMappingURL=bundle.js.map

packages/esbuild/test/workspace-mapping/main.js

@@ -0,0 +1,4 @@
+import {getId as m1Id} from 'build_bazel_rules_nodejs/module-one';
+import {getId as m2Id} from 'build_bazel_rules_nodejs/module-two';
+
+export default `Full ID: ${m1Id} - ${m2Id}`;

packages/esbuild/test/workspace-mapping/module-one/BUILD.bazel

@@ -0,0 +1,8 @@
+load("//internal/js_library:js_library.bzl", "js_library")
+
+package(default_visibility = ["//packages/esbuild/test:__subpackages__"])
+
+js_library(
+    name = "module-one",
+    srcs = [":index.js"],
+)

packages/esbuild/test/workspace-mapping/module-one/index.js

@@ -0,0 +1 @@
+export const getId = () => 'module-one';

packages/esbuild/test/workspace-mapping/module-two/BUILD.bazel

@@ -0,0 +1,8 @@
+load("//internal/js_library:js_library.bzl", "js_library")
+
+package(default_visibility = ["//packages/esbuild/test:__subpackages__"])
+
+js_library(
+    name = "module-two",
+    srcs = [":index.js"],
+)

packages/esbuild/test/workspace-mapping/module-two/index.js

@@ -0,0 +1 @@
+export const getId = () => 'module-two';