feat: init pin-inputs script

apps/pin-inputs/src/app.ts

@@ -0,0 +1,60 @@
+import { readFileSync, writeFileSync } from 'fs';
+
+export const replaceInFile = (replace: RegExp, replacement: string, file: string) => {
+    const fileContents = readFileSync(file);
+
+    const replaced = fileContents.toString().replace(replace, replacement);
+
+    writeFileSync(file, replaced);
+};
+
+/* Constants */
+const FLAKE = process.env.FLAKE;
+
+if (!FLAKE) {
+    console.error('Environment variable FLAKE not found');
+    process.exit(1);
+}
+
+const FLAKE_LOCK = JSON.parse(readFileSync(`${FLAKE}/flake.lock`, 'utf8')).nodes;
+const INPUT_REVS = new Map<string, string>();
+
+Object.entries(FLAKE_LOCK).forEach(([key, val]) => {
+    if (key !== 'root') {
+        // eslint-disable-next-line
+        INPUT_REVS.set(key, (val as any).locked.rev);
+    }
+});
+
+const INPUTS = process.argv.slice(2);
+
+
+/**
+ * Gets the commit hash of the specified input in this flake.
+ *
+ * @param input the name of the input
+ * @returns the commit hash
+ */
+const getCurrentRev = (input: string): string => {
+    if (!INPUT_REVS.has(input)) {
+        throw new Error(`Input ${input} could not be found.`);
+    }
+
+    return INPUT_REVS.get(input) as string;
+};
+
+INPUTS.forEach((input) => {
+    try {
+        const inputsFile = `${FLAKE}/inputs/default.nix`;
+        const rev = getCurrentRev(input);
+
+        replaceInFile(
+            new RegExp(`(\\n[ ]*)${input} =.*\\n.*\\n.*`),
+            `$&\n$1  # FIXME: $1  rev = "${rev}";`,
+            inputsFile,
+        );
+    }
+    catch (e) {
+        console.error((e as Error).message);
+    }
+});