fix(builtin): use correct genrule-style make vars

https://docs.bazel.build/versions/master/be/make-variables.html documents that $@ is for the output location of a single out
and $(RULEDIR) is the preferred way to refer to the output directory of the package

BREAKING CHANGE:
Usage of the $@ shortcut in npm_package_bin-generated rules should now be $(RULEDIR)
and you can now use $@ to refer to the location of a single output

Author: alexeagle

e2e/ts_devserver/subpackage/BUILD.bazel

@@ -23,7 +23,7 @@ html_insert_assets(
         "--html",
         "$(location index.tmpl.html)",
         "--out",
-        "$(location index.html)",
+        "$@",
         "--assets",
         "$(location //:red-body-style.css)",
     ],

examples/angular/src/BUILD.bazel

@@ -93,7 +93,7 @@ html_insert_assets(
         "--html",
         "$(location //src:example/index.html)",
         "--out",
-        "$(location index.html)",
+        "$@",
         "--assets",
     ] + ["$(location %s)" % s for s in _ASSETS] + [
         # This file doesn't exist during the build, but will be served by ts_devserver
@@ -154,7 +154,7 @@ babel(
         "--source-maps",
         "--presets=@babel/preset-env",
         "--out-dir",
-        "$@",
+        "$(RULEDIR)",
     ],
     data = [
         ":bundle-es2015",
@@ -184,7 +184,7 @@ html_insert_assets(
         "--html",
         "$(location //src:example/index.prod.html)",
         "--out",
-        "$(location _prodapp/src/example/index.html)",
+        "$@",
         "--assets",
     ] + ["$(location %s)" % s for s in _ASSETS],
     data = ["//src:example/index.prod.html"] + _ASSETS,

examples/angular_view_engine/src/BUILD.bazel

@@ -91,7 +91,7 @@ html_insert_assets(
         "--html",
         "$(location //src:example/index.html)",
         "--out",
-        "$(location index.html)",
+        "$@",
         "--assets",
     ] + ["$(location %s)" % s for s in _ASSETS] + [
         # This file doesn't exist during the build, but will be served by ts_devserver
@@ -154,7 +154,7 @@ babel(
         "--source-maps",
         "--presets=@babel/preset-env",
         "--out-dir",
-        "$@",
+        "$(RULEDIR)",
     ],
     data = [
         ":bundle-es2015",
@@ -184,7 +184,7 @@ html_insert_assets(
         "--html",
         "$(location //src:example/index.prod.html)",
         "--out",
-        "$(location _prodapp/src/example/index.html)",
+        "$@",
         "--assets",
     ] + ["$(location %s)" % s for s in _ASSETS],
     data = ["//src:example/index.prod.html"] + _ASSETS,

examples/app/BUILD.bazel

@@ -43,11 +43,11 @@ html_insert_assets(
     outs = ["index.html"],
     args = [
         "--out",
-        "$(location index.html)",
+        "$@",
         "--html",
         "$(location :index.tmpl.html)",
         "--roots",
-        "$@",
+        "$(RULEDIR)",
         "--assets",
     ] + ["$(locations %s)" % a for a in _ASSETS],
     data = [":index.tmpl.html"] + _ASSETS,
@@ -77,8 +77,8 @@ tsc(
         "-p",
         "$(location tsconfig-test.json)",
         "--outDir",
-        # $@ is a shorthand for the dist/bin directory where Bazel requires we write outputs
-        "$@",
+        # $(RULEDIR) is a shorthand for the dist/bin directory where Bazel requires we write outputs
+        "$(RULEDIR)",
     ],
     data = [
         "app.e2e-spec.ts",

examples/closure/BUILD.bazel

@@ -9,7 +9,7 @@ google_closure_compiler(
         # --platform native would be faster but is failing on Windows
         "--platform=javascript",
         "--js=$(location hello.js)",
-        "--js_output_file=$(location bundle.js)",
+        "--js_output_file=$@",
     ],
     data = ["hello.js"],
 )

examples/protocol_buffers/yarn.lock

@@ -2419,6 +2419,11 @@ requirejs@2.3.5:
   resolved "https://registry.yarnpkg.com/requirejs/-/requirejs-2.3.5.tgz#617b9acbbcb336540ef4914d790323a8d4b861b0"
   integrity sha512-svnO+aNcR/an9Dpi44C7KSAy5fFGLtmPbaaCeQaklUz8BQhS64tWWIIlvEA5jrWICzlO/X9KSzSeXFnZdBu8nw==
 
+requirejs@2.3.6:
+  version "2.3.6"
+  resolved "https://registry.yarnpkg.com/requirejs/-/requirejs-2.3.6.tgz#e5093d9601c2829251258c0b9445d4d19fa9e7c9"
+  integrity sha512-ipEzlWQe6RK3jkzikgCupiTbTvm4S0/CAU5GlgptkN5SO6F3u0UD0K18wy6ErDqiCyP4J4YYe1HuAShvsxePLg==
+
 requires-port@^1.0.0:
   version "1.0.0"
   resolved "https://registry.yarnpkg.com/requires-port/-/requires-port-1.0.0.tgz#925d2601d39ac485e091cf0da5c6e694dc3dcaff"

examples/react_webpack/BUILD.bazel

@@ -20,7 +20,7 @@ tsc(
         "$(location index.tsx)",
         "$(location types.d.ts)",
         "--outDir",
-        "$@",
+        "$(RULEDIR)",
         "--lib",
         "es2015,dom",
         "--jsx",
@@ -42,7 +42,7 @@ webpack(
         "--config",
         "$(location webpack.config.js)",
         "-o",
-        "$(location app.bundle.js)",
+        "$@",
     ],
     data = [
         "index.js",

examples/webapp/differential_loading.bzl

@@ -38,7 +38,7 @@ def differential_loading(name, entry_point, srcs):
             "--config-file",
             "$(location es5.babelrc)",
             "--out-dir",
-            "$@",
+            "$(RULEDIR)",
         ],
     )
 

internal/node/npm_package_bin.bzl

@@ -26,8 +26,15 @@ def _expand_location(ctx, s):
         # We'll write into a newly created directory named after the rule
         outdir_segments.append(ctx.attr.name)
 
+    if not ctx.attr.output_dir:
+        if s.find("$@") != -1 and len(ctx.outputs.outs) > 1:
+            fail("""$@ substitution may only be used with a single out
+            Upgrading rules_nodejs? Maybe you need to switch from $@ to $(RULEDIR)
+            See https://github.com/bazelbuild/rules_nodejs/releases/tag/0.42.0""")
+        s = s.replace("$@", ctx.outputs.outs[0].path)
+
     # The list comprehension removes empty segments like if we are in the root package
-    s = s.replace("$@", "/".join([o for o in outdir_segments if o]))
+    s = s.replace("$(RULEDIR)", "/".join([o for o in outdir_segments if o]))
     return ctx.expand_location(s, targets = ctx.attr.data)
 
 def _inputs(ctx):
@@ -95,8 +102,10 @@ def npm_package_bin(tool = None, package = None, package_bin = None, data = [],
 
             Subject to 'Make variable' substitution.
             Can use $(location) expansion. See https://docs.bazel.build/versions/master/be/make-variables.html
-            You may also refer to the location of the output_dir with the special `$@` replacement, like genrule.
-            If output_dir=False then $@ will refer to the output directory for this package.
+            Like genrule, you may also use some syntax sugar for locations:
+            - `$@`: if you have only one output file, the location of the output
+            - `$(RULEDIR)`: the output directory of the rule, corresponding with its package
+                (can be used with output_dir=True or False)
 
         package: an npm package whose binary to run, like "terser". Assumes your node_modules are installed in a workspace called "npm"
         package_bin: the "bin" entry from `package` that should be run. By default package_bin is the same string as `package`

internal/node/test/BUILD.bazel

@@ -151,7 +151,7 @@ npm_package_bin(
     args = [
         "$(location terser_input.js)",
         "--output",
-        "$(location minified.js)",
+        "$@",
     ],
     data = ["terser_input.js"],
     package = "terser",
@@ -166,7 +166,7 @@ npm_package_bin(
     name = "dir_output",
     args = [
         "--output-dir",
-        "$@",
+        "$(RULEDIR)",
         "$(location terser_input.js)",
     ],
     data = ["terser_input.js"],