Add JS-specific bits to Actions

src/nix.ts

@@ -0,0 +1,20 @@
+// Build the Nix args out of inputs from the Actions environment
+export function makeNixCommandArgs(
+  nixOptions: string[],
+  flakeInputs: string[],
+  commitMessage: string,
+): string[] {
+  const flakeInputFlags = flakeInputs.flatMap((input) => [
+    "--update-input",
+    input,
+  ]);
+
+  return nixOptions
+    .concat(["flake", "lock"])
+    .concat(flakeInputFlags)
+    .concat([
+      "--commit-lock-file",
+      "--commit-lock-file-summary",
+      `"${commitMessage}"`,
+    ]);
+}