feat(typescript): accept TsConfigInfo in extends

packages/typescript/internal/ts_config.bzl

@@ -99,29 +99,22 @@ write_tsconfig_rule = rule(
 )
 
 # Syntax sugar around skylib's write_file
-def write_tsconfig(name, config, files, extends, out):
+def write_tsconfig(name, config, files, out, extends = None):
     """Wrapper around bazel_skylib's write_file which understands tsconfig paths
 
     Args:
         name: name of the resulting write_file rule
         config: tsconfig dictionary
         files: list of input .ts files to put in the files[] array
-        extends: a tsconfig.json file to extend from
         out: the file to write
+        extends: a label for a tsconfig.json file to extend from, if any
     """
 
-    # Allow extends to be a list of labels, as this is what ts_project accepts
-    if type(extends) == type([]):
-        if len(extends):
-            extends = extends[0]
-        else:
-            extends = None
     if extends:
-        extends = Label(extends)
-        config["extends"] = "__extends__"  #_join(workspace_root, extends.package, extends.name)
+        config["extends"] = "__extends__"
 
     amended_config = struct(
-        files = "__files__",  #[_join(workspace_root, native.package_name(), f) for f in files],
+        files = "__files__",
         **config
     )
     write_tsconfig_rule(

packages/typescript/internal/ts_project.bzl

@@ -105,12 +105,17 @@ def _ts_project_impl(ctx):
             deps_depsets.append(dep[DeclarationInfo].transitive_declarations)
 
     inputs = ctx.files.srcs + depset(transitive = deps_depsets).to_list()
+
+    # Gather TsConfig info from both the direct (tsconfig) and indirect (extends) attribute
     if TsConfigInfo in ctx.attr.tsconfig:
         inputs.extend(ctx.attr.tsconfig[TsConfigInfo].deps)
     else:
         inputs.append(ctx.file.tsconfig)
-    if ctx.attr.extends:
-        inputs.extend(ctx.files.extends)
+    for extend in ctx.attr.extends:
+        if TsConfigInfo in extend:
+            inputs.extend(extend[TsConfigInfo].deps)
+        else:
+            inputs.extend(extend.files.to_list())
 
     # We do not try to predeclare json_outs, because their output locations generally conflict with their path in the source tree.
     # (The exception is when out_dir is used, then the .json output is a different path than the input.)
@@ -374,7 +379,10 @@ def ts_project_macro(
 
         deps: List of labels of other rules that produce TypeScript typings (.d.ts files)
 
-        tsconfig: Label of the tsconfig.json file to use for the compilation, or a target that provides TsConfigInfo.
+        tsconfig: Label of the tsconfig.json file to use for the compilation
+
+            To support "chaining" of more than one extended config, this label could be a target that
+            provdes `TsConfigInfo` such as `ts_config`.
 
             By default, we assume the tsconfig file is named by adding `.json` to the `name` attribute.
 
@@ -407,10 +415,15 @@ def ts_project_macro(
             )
             ```
 
-        extends: List of labels of tsconfig file(s) referenced in `extends` section of tsconfig.
+        extends: Label of the tsconfig file referenced in the `extends` section of tsconfig
 
-            Any tsconfig files "chained" by extends clauses must either be transitive deps of the TsConfigInfo
-            provided to the `tsconfig` attribute, or must be explicitly listed here.
+            To support "chaining" of more than one extended config, this label could be a target that
+            provdes `TsConfigInfo` such as `ts_config`.
+
+            _DEPRECATED, to be removed in 3.0_:
+            For backwards compatibility, this accepts a list of Labels of the "chained"
+            tsconfig files. You should instead use a single Label of a `ts_config` target.
+            Follow this deprecation: https://github.com/bazelbuild/rules_nodejs/issues/2140
 
         args: List of strings of additional command-line arguments to pass to tsc.
 
@@ -460,6 +473,10 @@ def ts_project_macro(
     extra_deps = []
 
     if type(tsconfig) == type(dict()):
+        # Opt-in to #2140 breaking change at the same time you opt-in to experimental tsconfig dict
+        if type(extends) == type([]):
+            fail("when tsconfig is a dict, extends should have a single value")
+
         # Copy attributes <-> tsconfig properties
         # TODO: fail if compilerOptions includes a conflict with an attribute?
         compiler_options = tsconfig.setdefault("compilerOptions", {})
@@ -482,7 +499,7 @@ def ts_project_macro(
             name = "_gen_tsconfig_%s" % name,
             config = tsconfig,
             files = srcs,
-            extends = extends,
+            extends = Label("//%s:%s" % (native.package_name(), name)).relative(extends) if extends else None,
             out = "tsconfig_%s.json" % name,
         )
 
@@ -513,6 +530,10 @@ def ts_project_macro(
     typings_out_dir = declaration_dir if declaration_dir else out_dir
     tsbuildinfo_path = ts_build_info_file if ts_build_info_file else name + ".tsbuildinfo"
 
+    # Backcompat for extends as a list, to cleanup in #2140
+    if (type(extends) == type("")):
+        extends = [extends]
+
     ts_project(
         name = name,
         srcs = srcs,

packages/typescript/test/ts_project/generated_tsconfig/extends/BUILD.bazel

@@ -1,19 +1,50 @@
 load("@build_bazel_rules_nodejs//:index.bzl", "generated_file_test")
-load("//packages/typescript:index.bzl", "ts_project")
+load("//packages/typescript:index.bzl", "ts_config", "ts_project")
 
+# Case one: extend from a single tsconfig
 ts_project(
-    extends = ["//packages/typescript/test/ts_project:tsconfig-base.json"],
+    name = "case_one",
+    extends = "//packages/typescript/test/ts_project:tsconfig-base.json",
     tsconfig = {
         "compilerOptions": {
             "declaration": True,
+            "outDir": "case_one",
             "types": [],
         },
     },
 )
 
+ts_config(
+    name = "tsconfig_chain",
+    src = "tsconfig-extended.json",
+    deps = [
+        "//packages/typescript/test/ts_project:tsconfig",
+    ],
+)
+
+# Case two: extend from a chain of tsconfig
+ts_project(
+    name = "case_two",
+    extends = ":tsconfig_chain",
+    tsconfig = {
+        "compilerOptions": {
+            "declaration": True,
+            "outDir": "case_two",
+            "types": [],
+        },
+    },
+)
+
+generated_file_test(
+    name = "test_one",
+    # test the default output of the ts_project
+    src = "expected.js_",
+    generated = "case_one/a.js",
+)
+
 generated_file_test(
-    name = "test",
+    name = "test_two",
     # test the default output of the ts_project
     src = "expected.js_",
-    generated = "a.js",
+    generated = "case_two/a.js",
 )

packages/typescript/test/ts_project/generated_tsconfig/extends/tsconfig-extended.json

@@ -0,0 +1,6 @@
+{
+    "extends": "../../tsconfig-base",
+    "compilerOptions": {
+        "declaration": true
+    },
+}

packages/typescript/test/ts_project/ts_config_info/BUILD.bazel

@@ -5,7 +5,7 @@ Test a tree of tsconfig.json files
 load("//packages/typescript:index.bzl", "ts_config", "ts_project")
 
 ts_config(
-    name = "tsconfig.abcd",
+    name = "tsconfig",
     src = "tsconfig.json",
     deps = [
         "tsconfig-extended.json",
@@ -17,6 +17,5 @@ ts_project(
     name = "compile_ts",
     composite = True,
     declaration = True,
-    # We'll name the tsbuildinfo output after tsconfig[:-5] so fool it for now
-    tsconfig = "tsconfig.abcd",
+    tsconfig = "tsconfig",
 )