refactor: named utility for cases where we must have a meaningless ou…

…tput for exit code

example/test/Dockerfile

@@ -0,0 +1,6 @@
+# If bats isn't working on your local machine, you can run it in this container.
+# rules_lint% docker build example/test -t bazel.build/bats
+# rules_lint% docker run -it -v "$PWD:/code" bazel.build/bats /code/example/test
+FROM bats/bats
+RUN echo https://dl-cdn.alpinelinux.org/alpine/edge/testing >> /etc/apk/repositories
+RUN apk add bazel

lint/clang_tidy.bzl

@@ -39,7 +39,7 @@ clang_tidy = lint_clang_tidy_aspect(
 
 load("@bazel_tools//tools/build_defs/cc:action_names.bzl", "ACTION_NAMES")
 load("@bazel_tools//tools/cpp:toolchain_utils.bzl", "find_cpp_toolchain")
-load("//lint/private:lint_aspect.bzl", "LintOptionsInfo", "dummy_successful_lint_action", "patch_and_report_files", "report_files")
+load("//lint/private:lint_aspect.bzl", "LintOptionsInfo", "discard_exit_code", "dummy_successful_lint_action", "patch_and_report_files", "report_files")
 
 _MNEMONIC = "AspectRulesLintClangTidy"
 
@@ -238,8 +238,7 @@ def clang_tidy_action(ctx, compilation_context, executable, srcs, stdout, exit_c
     outputs = [stdout]
     env = {}
     env["CLANG_TIDY__STDOUT_STDERR_OUTPUT_FILE"] = stdout.path
-    if exit_code == "discard":
-        exit_code = ctx.actions.declare_file("_exit_code_discard", sibling = stdout)
+
     if exit_code:
         env["CLANG_TIDY__EXIT_CODE_OUTPUT_FILE"] = exit_code.path
         outputs.append(exit_code)
@@ -325,7 +324,7 @@ def _clang_tidy_aspect_impl(target, ctx):
             clang_tidy_action(ctx, compilation_context, ctx.executable, files_to_lint, stdout, exit_code)
 
     # Run again for machine-readable output, only if rules_lint_report output_group is requested
-    clang_tidy_action(ctx, compilation_context, ctx.executable, files_to_lint, report, exit_code = "discard")
+    clang_tidy_action(ctx, compilation_context, ctx.executable, files_to_lint, report, exit_code = discard_exit_code(_MNEMONIC, target, ctx))
     return [info]
 
 def lint_clang_tidy_aspect(binary, configs = [], global_config = [], header_filter = "", lint_target_headers = False, angle_includes_are_system = True, verbose = False):

lint/eslint.bzl

@@ -55,7 +55,7 @@ See the [react example](https://github.com/bazelbuild/examples/blob/b498bb106b20
 
 load("@aspect_bazel_lib//lib:copy_to_bin.bzl", "COPY_FILE_TO_BIN_TOOLCHAINS", "copy_files_to_bin_actions")
 load("@aspect_rules_js//js:libs.bzl", "js_lib_helpers")
-load("//lint/private:lint_aspect.bzl", "LintOptionsInfo", "dummy_successful_lint_action", "filter_srcs", "patch_and_report_files", "report_files", "should_visit")
+load("//lint/private:lint_aspect.bzl", "LintOptionsInfo", "discard_exit_code", "dummy_successful_lint_action", "filter_srcs", "patch_and_report_files", "report_files", "should_visit")
 
 _MNEMONIC = "AspectRulesLintESLint"
 
@@ -113,9 +113,6 @@ def eslint_action(ctx, executable, srcs, stdout, exit_code = None, format = "sty
         file_inputs.append(format)
     args.add_all([s.short_path for s in srcs])
 
-    if exit_code == "discard":
-        exit_code = ctx.actions.declare_file("_discard_eslint_exit_code", sibling = stdout)
-
     if not exit_code:
         ctx.actions.run_shell(
             inputs = _gather_inputs(ctx, srcs, file_inputs),
@@ -212,7 +209,7 @@ def _eslint_aspect_impl(target, ctx):
             eslint_action(ctx, ctx.executable, files_to_lint, stdout, exit_code)
 
     # Run again for machine-readable output, only if rules_lint_report output_group is requested
-    eslint_action(ctx, ctx.executable, files_to_lint, report, exit_code = "discard", format = ctx.attr._formatter)
+    eslint_action(ctx, ctx.executable, files_to_lint, report, exit_code = discard_exit_code(_MNEMONIC, target, ctx), format = ctx.attr._formatter)
 
     return [info]
 

lint/private/lint_aspect.bzl

@@ -46,6 +46,13 @@ def should_visit(rule, allow_kinds, allow_filegroup_tags = []):
 
 _OUTFILE_FORMAT = "{label}.{mnemonic}.{suffix}"
 
+def discard_exit_code(mnemonic, target, ctx):
+    """Utility to declare an output file which will never be read.
+
+    Needed as a workaround for js_binary which accepts an output file for the exit code,
+    allowing it to return 0 even if the spawned binary exits non-zero."""
+    return ctx.actions.declare_file(_OUTFILE_FORMAT.format(label = target.label.name, mnemonic = mnemonic, suffix = "exit_code.discard"))
+
 def report_files(mnemonic, target, ctx):
     """Declare linter output files.