build: ship schematic code with ES2015 as target

This commit switches the schematic code to build as ES2015. This is
necessary to support Node v12 which is still supported in LTS mode

Author: devversion

src/cdk/schematics/BUILD.bazel

@@ -22,10 +22,12 @@ ts_library(
             "testing/**/*.ts",
         ],
     ),
+    devmode_module = "commonjs",
     # Schematics can not yet run in ESM module. For now we continue to use CommonJS.
     # TODO(ESM): remove this once the Angular CLI supports ESM schematics.
-    devmode_module = "commonjs",
+    devmode_target = "es2015",
     prodmode_module = "commonjs",
+    prodmode_target = "es2015",
     tsconfig = ":tsconfig.json",
     deps = [
         "//src/cdk/schematics/update-tool",

src/cdk/schematics/update-tool/BUILD.bazel

@@ -5,10 +5,12 @@ package(default_visibility = ["//visibility:public"])
 ts_library(
     name = "update-tool",
     srcs = glob(["**/*.ts"]),
+    devmode_module = "commonjs",
     # Schematics can not yet run in ESM module. For now we continue to use CommonJS.
     # TODO(ESM): remove this once the Angular CLI supports ESM schematics.
-    devmode_module = "commonjs",
+    devmode_target = "es2015",
     prodmode_module = "commonjs",
+    prodmode_target = "es2015",
     tsconfig = ":tsconfig.json",
     deps = [
         "@npm//@types/node",

src/material/schematics/BUILD.bazel

@@ -23,10 +23,12 @@ ts_library(
             "ng-generate/*/files/**/*.ts",
         ],
     ),
+    devmode_module = "commonjs",
     # Schematics do not need to run in browsers and can use `commonjs`
     # as format instead the default `umd` format.
-    devmode_module = "commonjs",
+    devmode_target = "es2015",
     prodmode_module = "commonjs",
+    prodmode_target = "es2015",
     tsconfig = ":tsconfig.json",
     deps = [
         "//src/cdk/schematics",

tools/defaults.bzl

@@ -65,7 +65,15 @@ def sass_library(**kwargs):
 def npm_sass_library(**kwargs):
     _npm_sass_library(**kwargs)
 
-def ts_library(tsconfig = None, deps = [], testonly = False, devmode_module = None, **kwargs):
+def ts_library(
+        tsconfig = None,
+        deps = [],
+        testonly = False,
+        # TODO(devversion): disallow configuration of the target when schematics use ESM.
+        devmode_target = None,
+        prodmode_target = None,
+        devmode_module = None,
+        **kwargs):
     # Add tslib because we use import helpers for all public packages.
     local_deps = ["@npm//tslib"] + deps
 
@@ -85,10 +93,10 @@ def ts_library(tsconfig = None, deps = [], testonly = False, devmode_module = No
         # For prodmode, the target is set to `ES2020`. `@bazel/typecript` sets `ES2015` by default. Note
         # that this should be in sync with the `ng_module` tsconfig generation to emit proper APF v13.
         # https://github.com/bazelbuild/rules_nodejs/blob/901df3868e3ceda177d3ed181205e8456a5592ea/third_party/github.com/bazelbuild/rules_typescript/internal/common/tsconfig.bzl#L195
-        prodmode_target = "es2020",
+        prodmode_target = prodmode_target if prodmode_target != None else "es2020",
         # We also set devmode output to the same settings as prodmode as a first step in combining
         # devmode and prodmode output. We will not rely on AMD output anyway due to the linker processing.
-        devmode_target = "es2020",
+        devmode_target = devmode_target if devmode_target != None else "es2020",
         devmode_module = devmode_module if devmode_module != None else "esnext",
         tsconfig = tsconfig,
         testonly = testonly,