Add ts_declaration rule.

Author: ribrdb

defs.bzl

@@ -17,13 +17,14 @@
 Users should not load files under "/internal"
 """
 load("//internal:ts_repositories.bzl", _ts_setup_workspace = "ts_setup_workspace")
-load("//internal:build_defs.bzl", _ts_library = "ts_library")
+load("//internal:build_defs.bzl", _ts_library = "ts_library", _ts_declaration="ts_declaration")
 load("//internal:ts_config.bzl", _ts_config = "ts_config")
 load("//internal/devserver:ts_devserver.bzl", _ts_devserver = "ts_devserver_macro")
 load("//internal/karma:ts_web_test.bzl", _ts_web_test = "ts_web_test_macro")
 
 ts_setup_workspace = _ts_setup_workspace
 ts_library = _ts_library
+ts_declaration = _ts_declaration
 ts_config = _ts_config
 ts_devserver = _ts_devserver
 # TODO(alexeagle): make ts_web_test work in google3

internal/build_defs.bzl

@@ -183,3 +183,54 @@ ts_library = rule(
         "tsconfig": "%{name}_tsconfig.json"
     }
 )
+
+def _ts_declaration_impl(ctx):
+  """Implementation of ts_declaration.
+
+  Args:
+    ctx: the context.
+
+  Returns:
+    the struct returned by the call to compile_ts.
+  """
+  ts_providers = compile_ts(ctx, is_library=False,
+                            compile_action=_compile_action,
+                            devmode_compile_action=_devmode_compile_action,
+                            tsc_wrapped_tsconfig=tsc_wrapped_tsconfig)
+  return ts_providers_dict_to_struct(ts_providers)
+
+ts_declaration = rule(
+    _ts_declaration_impl,
+    attrs = dict(COMMON_ATTRIBUTES, **{
+        "srcs":
+            attr.label_list(
+                allow_files=FileType([
+                    ".ts",
+                    ".tsx",
+                ]),
+                mandatory=True,),
+
+        # TODO(alexeagle): reconcile with google3: ts_library rules should
+        # be portable across internal/external, so we need this attribute
+        # internally as well.
+        "tsconfig":
+            attr.label(allow_files = True, single_file = True),
+        "compiler":
+            attr.label(
+                default=get_tsc(),
+                single_file=False,
+                allow_files=True,
+                executable=True,
+                cfg="host"),
+        "supports_workers": attr.bool(default = True),
+        "tsickle_typed": attr.bool(default = True),
+        "_tsc_wrapped_deps": attr.label(default = Label("@build_bazel_rules_typescript_tsc_wrapped_deps//:node_modules")),
+        # @// is special syntax for the "main" repository
+        # The default assumes the user specified a target "node_modules" in their
+        # root BUILD file.
+        "node_modules": attr.label(default = Label("@//:node_modules")),
+    }),
+    outputs = {
+        "tsconfig": "%{name}_tsconfig.json"
+    }
+)

internal/common/compilation.bzl

@@ -197,8 +197,9 @@ def compile_ts(ctx,
 
   if hasattr(ctx.attr,'tsickle_typed') and ctx.attr.tsickle_typed:
     if has_sources and ctx.attr.runtime != "nodejs":
-      # Note: setting this variable controls whether tsickle is run at all.
-      tsickle_externs = [ctx.new_file(ctx.label.name + ".externs.js")]
+      if is_library or ctx.attr.generate_externs:
+        # Note: setting this variable controls whether tsickle is run at all.
+        tsickle_externs = [ctx.new_file(ctx.label.name + ".externs.js")]
 
   dep_declarations = _collect_dep_declarations(ctx)
   input_declarations = dep_declarations.transitive + src_declarations