Create script to run a command iff it's available on the PATH

... and use it to run actionlint and ShellCheck.

.eslintrc.yml

@@ -122,6 +122,7 @@ rules:
     - error
     - allowedLicenses:
         - MIT
+        - MIT-0
         - MPL-2.0
       numericOnlyVariation: false
   jsdoc/empty-tags:

package.json

@@ -111,12 +111,12 @@
     "format:check": "npm run _prettier -- --check",
     "fuzz": "node script/fuzz.js",
     "license-check": "licensee --errors-only",
-    "lint": "npm run lint:js && npm run lint:json && npm run lint:md && npm run lint:yml",
-    "lint:ci": "actionlint",
+    "lint": "npm run lint:ci && npm run lint:js && npm run lint:json && npm run lint:md && npm run lint:sh && npm run lint:yml",
+    "lint:ci": "node script/maybe-run.js actionlint",
     "lint:js": "npm run _eslint -- --ext .js,.cjs",
     "lint:json": "npm run _eslint -- --ext .json,.jsonc",
     "lint:md": "markdownlint --dot --ignore-path .gitignore .",
-    "lint:sh": "shellcheck script/hooks/*.sh script/hooks/pre-*",
+    "lint:sh": "node script/maybe-run.js shellcheck script/hooks/*.sh script/hooks/pre-*",
     "lint:yml": "npm run _eslint -- --ext .yml",
     "mutation": "npm run mutation:unit && npm run mutation:integration",
     "mutation:integration": "stryker run stryker.integration.config.js",

script/_common.js

@@ -22,6 +22,13 @@ export function isWindows() {
   return os.platform() === "win32";
 }
 
+export function spawnSync(cmd, argv) {
+  return cp.spawnSync(cmd, argv, {
+    cwd: projectRoot,
+    stdio: "inherit",
+  });
+}
+
 export function npm(argv) {
   return cp.spawn(npmCmd, argv, {
     cwd: projectRoot,

script/maybe-run.js

@@ -0,0 +1,31 @@
+/**
+ * @overview Run a tool if it's present on the PATH, otherwise output a warning.
+ * @license MIT-0
+ */
+
+import process from "node:process";
+
+import which from "which";
+
+import { common } from "./_.js";
+
+if (common.argv.length === 0) {
+  console.error("Provide a command to try and execute.");
+  process.exit(1);
+}
+
+const cmd = common.argv[0];
+const args = common.argv.slice(1);
+
+try {
+  which.sync(cmd);
+} catch (_) {
+  console.warn(
+    `Command '${cmd}' not found, it will not be run.`,
+    "Install it to make this warning go away.",
+  );
+  process.exit(0);
+}
+
+const { status } = common.spawnSync(cmd, args);
+process.exit(status);