From e16c7dacdb43a3b87afc949f54c3ace57688f9fb Mon Sep 17 00:00:00 2001
From: UebelAndre <github@uebelandre.com>
Date: Wed, 8 Jul 2026 06:51:44 -0700
Subject: [PATCH] Add path-mapping support

---
 README.md                             | 38 +++++++++++++++++++++++++++
 shellcheck/internal/BUILD.bazel       |  8 +++---
 shellcheck/internal/aspect_runner.bat | 26 +++++++++++++++---
 shellcheck/internal/aspect_runner.sh  | 13 +++++++--
 shellcheck/internal/rules.bzl         |  8 +++---
 5 files changed, 80 insertions(+), 13 deletions(-)

diff --git a/README.md b/README.md
index 5840c54..fbbe8aa 100644
--- a/README.md
+++ b/README.md
@@ -26,6 +26,44 @@ shellcheck_test(
 )
 ```
 
+## Configuring the shellcheck aspect
+
+`shellcheck_aspect` runs `shellcheck` against any target that provides `ShInfo` or `ShBinaryInfo` (e.g. `sh_binary` and `sh_library` from [rules_shell]) as part of a normal `bazel build`. Enable it by adding the following to your `.bazelrc`:
+
+```
+build --aspects=@rules_shellcheck//shellcheck:shellcheck_aspect.bzl%shellcheck_aspect
+build --output_groups=+shellcheck_checks
+```
+
+With those flags in place, any build that includes shell targets will also run `shellcheck` on their sources; the lint results are exposed via the `shellcheck_checks` output group.
+
+### Output format and severity
+
+The aspect reads two `string_flag` build settings. Override them on the command line or via `.bazelrc`:
+
+```
+build --@rules_shellcheck//shellcheck/settings:format=gcc
+build --@rules_shellcheck//shellcheck/settings:severity=warning
+```
+
+- `//shellcheck/settings:format` accepts `checkstyle`, `diff`, `gcc`, `json`, `json1`, `quiet`, or `tty` (default: `shellcheck`'s built-in default).
+- `//shellcheck/settings:severity` accepts `error`, `warning`, `info`, or `style` (default: `shellcheck`'s built-in default).
+
+Because these are standard `string_flag`s, you can also flip them per-command with `--config` groups or with [`transitions`][transitions] if you want a specific target to lint under different settings.
+
+### Skipping targets
+
+Add any of the following tags to a target to opt it out of `shellcheck_aspect`:
+
+- `no_shellcheck`
+- `noshellcheck`
+- `no_lint`
+- `nolint`
+
+Targets under external repositories (`workspace_root` starting with `external`) are always skipped.
+
 Note: this is a simple project that allows me to learn about various bazel concepts. Feel free to create PRs contributing to the project or consider using [rules_lint].
 
 [rules_lint]: https://github.com/aspect-build/rules_lint
+[rules_shell]: https://github.com/bazelbuild/rules_shell
+[transitions]: https://bazel.build/extending/config#user-defined-transitions
diff --git a/shellcheck/internal/BUILD.bazel b/shellcheck/internal/BUILD.bazel
index 7fa069f..faa0207 100644
--- a/shellcheck/internal/BUILD.bazel
+++ b/shellcheck/internal/BUILD.bazel
@@ -4,11 +4,11 @@ filegroup(
     visibility = ["//shellcheck:__pkg__"],
 )
 
-filegroup(
+alias(
     name = "aspect_runner",
-    srcs = select({
-        "@platforms//os:windows": ["aspect_runner.bat"],
-        "//conditions:default": ["aspect_runner.sh"],
+    actual = select({
+        "@platforms//os:windows": "aspect_runner.bat",
+        "//conditions:default": "aspect_runner.sh",
     }),
     visibility = ["//visibility:public"],
 )
diff --git a/shellcheck/internal/aspect_runner.bat b/shellcheck/internal/aspect_runner.bat
index fbc3752..91ba1a3 100755
--- a/shellcheck/internal/aspect_runner.bat
+++ b/shellcheck/internal/aspect_runner.bat
@@ -1,6 +1,24 @@
-#!/bin/sh
+@echo off
+setlocal enabledelayedexpansion
 
-set -eu
+set "output=%~1"
+shift
 
-echo "" > "${SHELLCHECK_ASPECT_OUTPUT}"
-exec $@
+if not "%~1"=="--" (
+    echo aspect_runner: expected '--' after output path, got: %~1 1>&2
+    exit /b 1
+)
+shift
+
+break > "%output%"
+
+set "cmd="
+:loop
+if "%~1"=="" goto :run
+set "cmd=!cmd! %1"
+shift
+goto :loop
+
+:run
+%cmd%
+exit /b %errorlevel%
diff --git a/shellcheck/internal/aspect_runner.sh b/shellcheck/internal/aspect_runner.sh
index fbc3752..9cc18d0 100755
--- a/shellcheck/internal/aspect_runner.sh
+++ b/shellcheck/internal/aspect_runner.sh
@@ -2,5 +2,14 @@
 
 set -eu
 
-echo "" > "${SHELLCHECK_ASPECT_OUTPUT}"
-exec $@
+output="$1"
+shift
+
+if [ "${1-}" != "--" ]; then
+    echo "aspect_runner: expected '--' after output path, got: ${1-}" >&2
+    exit 1
+fi
+shift
+
+echo "" > "${output}"
+exec "$@"
diff --git a/shellcheck/internal/rules.bzl b/shellcheck/internal/rules.bzl
index 9864231..0296d92 100644
--- a/shellcheck/internal/rules.bzl
+++ b/shellcheck/internal/rules.bzl
@@ -191,6 +191,8 @@ def _shellcheck_aspect_impl(target, ctx):
     tools = depset([toolchain.shellcheck], transitive = [toolchain.all_files])
 
     args = ctx.actions.args()
+    args.add(output)
+    args.add("--")
     args.add(toolchain.shellcheck)
     args.add(toolchain.shellcheckrc, format = "--rcfile=%s")
     args.add_all(src_info.source_paths, format_each = "--source-path=%s")
@@ -209,11 +211,11 @@ def _shellcheck_aspect_impl(target, ctx):
         executable = ctx.file._runner,
         inputs = depset(inputs_direct, transitive = inputs_transitive),
         arguments = [args],
-        env = ctx.configuration.default_shell_env | {
-            "SHELLCHECK_ASPECT_OUTPUT": output.path,
-        },
+        env = ctx.configuration.default_shell_env,
         tools = tools,
         outputs = [output],
+        execution_requirements = {"supports-path-mapping": ""},
+        toolchain = TOOLCHAIN_TYPE,
     )
 
     return [