test: add test of npm_import(patch_tool)

MODULE.bazel

@@ -270,6 +270,18 @@ npm.npm_translate_lock(
     npmrc = "//:.npmrc",
     pnpm_lock = "//:pnpm-lock.yaml",
 )
+npm.npm_import(
+    name = "npm__meaning-of-life__1.0.0",
+    integrity = "sha512-fVA4xSydqtK9owabGcYw1r4EKEsMOVVeYQLeCXPu77Z+8Y2j2B2I16UqZlKIOHnYkJ4RSvpJ00ywy9IWjmuxYw==",
+    package = "meaning-of-life",
+    patch_args = ["-p1"],
+    # A custom patch tool must be a pre-built binary or source file since repository
+    # rules cannot depend on the output of a build target.
+    patch_tool = "//npm/private/test:patch_tool.sh",
+    patches = ["//npm/private/test:meaning-of-life@1.0.0.patch"],
+    root_package = "npm/private/test",
+    version = "1.0.0",
+)
 use_repo(
     npm,
     "npm",
@@ -278,6 +290,8 @@ use_repo(
     "npm__es5-ext__0.10.64__links",
     "npm__fsevents__2.3.3__links",
     "npm__google-closure-compiler__20251111.0.0__links",
+    "npm__meaning-of-life__1.0.0",
+    "npm__meaning-of-life__1.0.0__links",
     "npm__rollup__4.55.2",
     "npm__rollup__4.55.2__links",
     "npm__unused__0.2.2__links",

npm/private/test/BUILD.bazel

@@ -2,6 +2,7 @@ load("@aspect_rules_js//js:defs.bzl", "js_test")
 load("@bazel_lib//lib:write_source_files.bzl", "write_source_files")
 load("@bazel_skylib//rules:build_test.bzl", "build_test")
 load("@npm//:defs.bzl", "npm_link_all_packages")
+load("@npm__meaning-of-life__1.0.0__links//:defs.bzl", "npm_link_imported_package")
 load("@rules_shell//shell:sh_test.bzl", "sh_test")
 load(":generated_pkg_json_test.bzl", "generated_pkg_json_test")
 load(":npm_auth_test.bzl", "npm_auth_failure_test_suite", "npm_auth_test_suite")
@@ -15,6 +16,15 @@ load(":utils_tests.bzl", "utils_tests")
 
 npm_link_all_packages()
 
+# Links the /MODULE npm_import() of meaning-of-life, patched with a custom `patch_tool`
+npm_link_imported_package()
+
+js_test(
+    name = "patch_tool_test",
+    data = [":node_modules/meaning-of-life"],
+    entry_point = "patch_tool_test.js",
+)
+
 # Unit tests
 utils_tests(name = "test_utils")
 

npm/private/test/meaning-of-life@1.0.0.patch

@@ -0,0 +1,7 @@
+diff --git a/index.js b/index.js
+index a8653a9c9264ca1ac9fd2acb6c523a321912ab33..ae967de93c7c12074a686e1e8437b7b2344108be 100644
+--- a/index.js
++++ b/index.js
+@@ -1 +1 @@
+-module.exports = 42
++module.exports = "forty two"

npm/private/test/patch_tool.sh

@@ -0,0 +1,8 @@
+#!/usr/bin/env bash
+set -o errexit -o nounset -o pipefail
+
+patch "$@"
+
+# Leave a trace only this custom tool would produce so the test can
+# distinguish it from the default `patch` from PATH.
+echo 'module.exports += " (custom patch_tool)"' >>index.js

npm/private/test/patch_tool_test.js

@@ -0,0 +1,7 @@
+const assert = require('node:assert')
+
+const meaningOfLife = require('meaning-of-life')
+
+// `meaning-of-life@1.0.0.patch` changes 42 to "forty two" and the custom
+// `patch_tool.sh` appends the " (custom patch_tool)" suffix.
+assert.strictEqual(meaningOfLife, 'forty two (custom patch_tool)')