Removes css_map() and inlines its implementation in css_bundle().

Refs #46.

The import map is only ever generated as part of `css_bundle()`. It needed to be a different rule before because `postcss_multi_binary()` was a macro and needed to be called at that level. But now that `css_bundle()` is a custom rule, we can generate the import map directly, which is much more straightforward.

packages/css_bundler/css_bundle.bzl

@@ -1,5 +1,5 @@
 load("@aspect_bazel_lib//lib:paths.bzl", "to_output_relative_path")
-load("//packages/rules_prerender/css:css_providers.bzl", "CssInfo")
+load("//packages/rules_prerender/css:css_providers.bzl", "CssImportMapInfo", "CssInfo")
 
 def _css_bundle_impl(ctx):
     # Map each direct dependency source file to an output of the same full file path
@@ -33,7 +33,10 @@ def _css_bundle_impl(ctx):
         },
     )
 
-    return DefaultInfo(files = depset(outputs))
+    return [
+        DefaultInfo(files = depset(outputs)),
+        CssImportMapInfo(import_map = _make_import_map(ctx, sources, outputs)),
+    ]
 
 css_bundle = rule(
     implementation = _css_bundle_impl,
@@ -63,3 +66,25 @@ def _workspace_short_path(file, current_wksp):
     else:
         # File is in the main workspace. Use the current workspace name.
         return "%s/%s" % (current_wksp, file.short_path)
+
+def _make_import_map(ctx, sources, outputs):
+    """Generates a map of import paths to the actual file location to import.
+    
+    When users call `inlineStyle()`, it resolves and looks up that path in this map
+    and actually inlines the file specified by the map. This allows the file path in
+    user code to differ from the actual path the bundled CSS file lives at.
+    """
+    import_map = dict()
+    for (source, output) in zip(sources, outputs):
+        wksp_path = _workspace_short_path(source, ctx.workspace_name)
+
+        if wksp_path in import_map:
+            fail("CSS library file (%s) mapped twice, once to %s and a second time to %s." % (
+                wksp_path,
+                import_map[wksp_path].path,
+                output.path,
+            ))
+
+        import_map[wksp_path] = output
+
+    return import_map

packages/rules_prerender/css/BUILD.bazel

@@ -13,7 +13,6 @@ bzl_library(
     visibility = ["//packages/rules_prerender:__pkg__"],
     deps = [
         ":css_group",
-        ":css_map",
         ":css_providers",
         "//packages/rules_prerender:postcss_import_plugin",
     ],
@@ -36,12 +35,6 @@ bzl_library(
     deps = [":css_providers"],
 )
 
-bzl_library(
-    name = "css_map",
-    srcs = ["css_map.bzl"],
-    deps = [":css_providers"],
-)
-
 bzl_library(
     name = "css_providers",
     srcs = ["css_providers.bzl"],

packages/rules_prerender/css/css_binaries.bzl

@@ -2,7 +2,6 @@
 
 load("//packages/css_bundler:css_bundle.bzl", "css_bundle")
 load(":css_group.bzl", "css_group")
-load(":css_map.bzl", "css_map")
 load(":css_providers.bzl", "CssInfo")
 
 def css_binaries(
@@ -29,10 +28,20 @@ def css_binaries(
         visibility: https://docs.bazel.build/versions/main/be/common-definitions.html#common-attributes
         tags: https://docs.bazel.build/versions/main/be/common-definitions.html#common-attributes
     """
+    # It might look like this implementation should accept multiple `css_library()`
+    # targets, but doing so would be a bad idea. This is because the library is separated
+    # into "direct sources" and "transitive dependencies" which are fed into
+    # `css_bundle()`. If this allowed multiple libraries and same split was done, it
+    # would be "all libraries' direct sources" and "all libraries' transitive
+    # dependencies". This sounds reasonable, but would break strict deps. If one library
+    # had `@import './foo.css';` but forgot to add a dep on `:foo` yet another library in
+    # this binary had a dep on `:foo`, the first would incorrectly compile successfully.
+    # As a result, we need a separate `css_bundle()` for each compiled `css_library()`
+    # until we get proper strict deps support.
     binaries = []
     for (index, dep) in enumerate(deps):
         binary_name = "%s_binary_%s" % (name, index)
-        _css_binary(
+        css_bundle(
             name = binary_name,
             dep = dep,
             testonly = testonly,
@@ -47,61 +56,3 @@ def css_binaries(
         visibility = visibility,
         tags = tags,
     )
-
-# It might look like this implementation should accept multiple `css_library()` targets,
-# but doing so would be a bad idea. This is because the library is separated into "direct
-# sources" and "transitive dependencies" which are fed into `postcss_multi_binary()`. If
-# this allowed multiple libraries and same split was done, it would be "all libraries'
-# direct sources" and "all libraries' transitive dependencies". This sounds reasonable,
-# but would break strict deps. If one library had `@import url("rules_prerender/foo");`
-# but forgot to add a dep on `//:foo` yet another library in this binary had a dep on
-# `//:foo`, the first would incorrectly compile successfully. As a result, we need a
-# separate `postcss_multi_binary()` for each compiled `css_library()`.
-def _css_binary(
-    name,
-    dep,
-    testonly = None,
-    visibility = None,
-    tags = None,
-):
-    """Generates a CSS "binary" for a single `css_library()` dependency.
-    
-    The `css_library()` dependency gets each of its direct sources compiled into a
-    "binary", a new CSS file which bundles all the `@import` dependencies of that source.
-    Note that while this macro is called `_css_binary()` in the singular form, if the
-    `css_library()` dependency has multiple direct sources, each one will be compiled into
-    an independent "binary", meaning multiple binaries can be generated by this macro.
-
-    Returns:
-        `DefaultInfo`: Contains bundled CSS.
-        `CssImportMapInfo`: Maps importable paths to generated CSS binary files.
-
-    Args:
-        name: Name of this target.
-        dep: Dependency of this target which provides `CssInfo` (generally
-            `css_library()`).
-        testonly: https://docs.bazel.build/versions/main/be/common-definitions.html#common-attributes
-        visibility: https://docs.bazel.build/versions/main/be/common-definitions.html#common-attributes
-        tags: https://docs.bazel.build/versions/main/be/common-definitions.html#common-attributes
-    """
-    # Compile the CSS. This only compiles one library, but that library may have many
-    # source files, each one should be compiled into its own output, which requires
-    # `postcss_multi_binary()` even though `postcss_binary()` sounds like it would be
-    # sufficient here.
-    binary = "%s_parcel" % name
-    css_bundle(
-        name = binary,
-        dep = dep,
-        testonly = testonly,
-        tags = tags,
-    )
-
-    # Return the binary outputs with a map of import name -> file path.
-    css_map(
-        name = name,
-        bin = ":%s" % binary,
-        lib = dep,
-        testonly = testonly,
-        visibility = visibility,
-        tags = tags,
-    )

packages/rules_prerender/css/tests/group/group_test.bzl

@@ -11,8 +11,8 @@ def _css_group_test_impl(ctx):
     # Verify that `css_group()` re-exports `DefaultInfo`.
     default_info = analysistest.target_under_test(env)[DefaultInfo]
     expected_files = sets.make([
-        "packages/rules_prerender/css/tests/group/bin1_binary_0_parcel/rules_prerender/packages/rules_prerender/css/tests/group/lib1.css",
-        "packages/rules_prerender/css/tests/group/bin2_binary_0_parcel/rules_prerender/packages/rules_prerender/css/tests/group/lib2.css",
+        "packages/rules_prerender/css/tests/group/bin1_binary_0/rules_prerender/packages/rules_prerender/css/tests/group/lib1.css",
+        "packages/rules_prerender/css/tests/group/bin2_binary_0/rules_prerender/packages/rules_prerender/css/tests/group/lib2.css",
     ])
     actual_files = sets.make([file.short_path for file in default_info.files.to_list()])
     asserts.new_set_equals(env, expected_files, actual_files)
@@ -22,11 +22,11 @@ def _css_group_test_impl(ctx):
     import_map = css_import_map.import_map
     asserts.equals(env, 2, len(import_map.items()))
 
-    expected_lib1 = "packages/rules_prerender/css/tests/group/bin1_binary_0_parcel/rules_prerender/packages/rules_prerender/css/tests/group/lib1.css"
+    expected_lib1 = "packages/rules_prerender/css/tests/group/bin1_binary_0/rules_prerender/packages/rules_prerender/css/tests/group/lib1.css"
     actual_lib1 = import_map["rules_prerender/packages/rules_prerender/css/tests/group/lib1.css"].short_path
     asserts.equals(env, expected_lib1, actual_lib1)
 
-    expected_lib2 = "packages/rules_prerender/css/tests/group/bin2_binary_0_parcel/rules_prerender/packages/rules_prerender/css/tests/group/lib2.css"
+    expected_lib2 = "packages/rules_prerender/css/tests/group/bin2_binary_0/rules_prerender/packages/rules_prerender/css/tests/group/lib2.css"
     actual_lib2 = import_map["rules_prerender/packages/rules_prerender/css/tests/group/lib2.css"].short_path
     asserts.equals(env, expected_lib2, actual_lib2)
 
@@ -80,9 +80,9 @@ def _css_group_fails_with_conflicting_maps_test_impl(ctx):
         "rules_prerender/packages/rules_prerender/css/tests/group/conflicting_lib.css")
     # Look for conflicting file paths.
     asserts.expect_failure(env,
-        "packages/rules_prerender/css/tests/group/conflicting_bin1_binary_0_parcel/rules_prerender/packages/rules_prerender/css/tests/group/conflicting_lib.css")
+        "packages/rules_prerender/css/tests/group/conflicting_bin1_binary_0/rules_prerender/packages/rules_prerender/css/tests/group/conflicting_lib.css")
     asserts.expect_failure(env,
-        "packages/rules_prerender/css/tests/group/conflicting_bin2_binary_0_parcel/rules_prerender/packages/rules_prerender/css/tests/group/conflicting_lib.css")
+        "packages/rules_prerender/css/tests/group/conflicting_bin2_binary_0/rules_prerender/packages/rules_prerender/css/tests/group/conflicting_lib.css")
 
     return analysistest.end(env)
 

packages/rules_prerender/css/tests/import_map/import_map_test.bzl

@@ -10,11 +10,11 @@ def _import_map_test_impl(ctx):
     import_map = css_import_map.import_map
     asserts.equals(env, 2, len(import_map.items()))
 
-    expected_foo = "packages/rules_prerender/css/tests/import_map/bin_binary_0_parcel/rules_prerender/packages/rules_prerender/css/tests/import_map/foo.css"
+    expected_foo = "packages/rules_prerender/css/tests/import_map/bin_binary_0/rules_prerender/packages/rules_prerender/css/tests/import_map/foo.css"
     actual_foo = import_map["rules_prerender/packages/rules_prerender/css/tests/import_map/foo.css"].short_path
     asserts.equals(env, expected_foo, actual_foo)
 
-    expected_bar = "packages/rules_prerender/css/tests/import_map/bin_binary_0_parcel/rules_prerender/packages/rules_prerender/css/tests/import_map/bar.css"
+    expected_bar = "packages/rules_prerender/css/tests/import_map/bin_binary_0/rules_prerender/packages/rules_prerender/css/tests/import_map/bar.css"
     actual_bar = import_map["rules_prerender/packages/rules_prerender/css/tests/import_map/bar.css"].short_path
     asserts.equals(env, expected_bar, actual_bar)
 
@@ -49,7 +49,7 @@ def _import_map_from_different_packages_test_impl(ctx):
 
     # Import path contains `subpackage` because that's what the user would import.
     # But the actual file it points to uses the same name in the `css_binaries()` package.
-    expected_lib = "packages/rules_prerender/css/tests/import_map/different_packages_bin_binary_0_parcel/rules_prerender/packages/rules_prerender/css/tests/import_map/subpackage/lib.css"
+    expected_lib = "packages/rules_prerender/css/tests/import_map/different_packages_bin_binary_0/rules_prerender/packages/rules_prerender/css/tests/import_map/subpackage/lib.css"
     actual_lib = import_map["rules_prerender/packages/rules_prerender/css/tests/import_map/subpackage/lib.css"].short_path
     asserts.equals(env, expected_lib, actual_lib)
 

packages/rules_prerender/prerender_component_publish_files_test.ts

@@ -20,7 +20,7 @@ describe('prerender_component_publish_files()', () => {
             'script_dep.d.ts',
             // Temporary bad assertion. Need to update component publishing to copy
             // styles into the correct position in the NPM package.
-            'component_styles_bin_binary_0_parcel',
+            'component_styles_bin_binary_0',
             'component_resources', // from `resources` attribute.
         ]);