Switch to a typescript based action

.eslintrc.json

@@ -0,0 +1,73 @@
+{
+  "plugins": ["@typescript-eslint"],
+  "extends": ["plugin:github/recommended"],
+  "parser": "@typescript-eslint/parser",
+  "parserOptions": {
+    "ecmaVersion": 9,
+    "sourceType": "module",
+    "project": "./tsconfig.json"
+  },
+  "settings": {
+    "import/resolver": {
+      "typescript": {}
+    }
+  },
+  "rules": {
+    "i18n-text/no-en": "off",
+    "eslint-comments/no-use": "off",
+    "import/no-namespace": "off",
+    "no-unused-vars": "off",
+    "@typescript-eslint/no-unused-vars": [
+      "error",
+      {
+        "argsIgnorePattern": "^_"
+      }
+    ],
+    "@typescript-eslint/explicit-member-accessibility": [
+      "error",
+      {
+        "accessibility": "no-public"
+      }
+    ],
+    "@typescript-eslint/no-require-imports": "error",
+    "@typescript-eslint/array-type": "error",
+    "@typescript-eslint/await-thenable": "error",
+    "@typescript-eslint/ban-ts-comment": "error",
+    "camelcase": "off",
+    "@typescript-eslint/consistent-type-assertions": "error",
+    "@typescript-eslint/explicit-function-return-type": [
+      "error",
+      {
+        "allowExpressions": true
+      }
+    ],
+    "@typescript-eslint/func-call-spacing": ["error", "never"],
+    "@typescript-eslint/no-array-constructor": "error",
+    "@typescript-eslint/no-empty-interface": "error",
+    "@typescript-eslint/no-explicit-any": "error",
+    "@typescript-eslint/no-floating-promises": "error",
+    "@typescript-eslint/no-extraneous-class": "error",
+    "@typescript-eslint/no-for-in-array": "error",
+    "@typescript-eslint/no-inferrable-types": "error",
+    "@typescript-eslint/no-misused-new": "error",
+    "@typescript-eslint/no-namespace": "error",
+    "@typescript-eslint/no-non-null-assertion": "warn",
+    "@typescript-eslint/no-unnecessary-qualifier": "error",
+    "@typescript-eslint/no-unnecessary-type-assertion": "error",
+    "@typescript-eslint/no-useless-constructor": "error",
+    "@typescript-eslint/no-var-requires": "error",
+    "@typescript-eslint/prefer-for-of": "warn",
+    "@typescript-eslint/prefer-function-type": "warn",
+    "@typescript-eslint/prefer-includes": "error",
+    "@typescript-eslint/prefer-string-starts-ends-with": "error",
+    "@typescript-eslint/promise-function-async": "error",
+    "@typescript-eslint/require-array-sort-compare": "error",
+    "@typescript-eslint/restrict-plus-operands": "error",
+    "@typescript-eslint/type-annotation-spacing": "error",
+    "@typescript-eslint/unbound-method": "error"
+  },
+  "env": {
+    "node": true,
+    "es6": true
+  }
+}

.gitattributes

@@ -0,0 +1,2 @@
+dist/* linguist-generated=true
+

.github/workflows/ci.yaml

@@ -6,11 +6,29 @@ on:
     branches: [main]
 
 jobs:
+  check-dist-up-to-date:
+    name: Check the dist/ folder is up to date
+    runs-on: ubuntu-22.04
+    permissions:
+      contents: read
+      id-token: write
+    steps:
+      - uses: actions/checkout@v4
+      - uses: DeterminateSystems/nix-installer-action@main
+      - uses: DeterminateSystems/magic-nix-cache-action@main
+      - run: nix develop --command pnpm install
+      - run: nix develop --command pnpm run format
+      - run: nix develop --command pnpm run lint
+      - run: nix develop --command pnpm run build
+      - run: nix develop --command pnpm run package
+      - run: git status --porcelain=v1
+      - run: test $(git status --porcelain=v1 2>/dev/null | wc -l) -eq 0
+
   run-x86_64-linux-clean:
     name: Run x86_64 Linux (clean)
     runs-on: ubuntu-22.04
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - name: Check flake.lock
         uses: ./
 
@@ -18,7 +36,7 @@ jobs:
     name: Run x86_64 Linux (dirty)
     runs-on: ubuntu-22.04
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - name: Check flake.lock
         uses: ./
         with:
@@ -28,7 +46,7 @@ jobs:
     name: Run x86_64 Darwin (clean)
     runs-on: macos-12
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - name: Check flake.lock
         uses: ./
 
@@ -36,7 +54,7 @@ jobs:
     name: Run x86_64 Darwin (dirty)
     runs-on: macos-12
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - name: Check flake.lock
         uses: ./
         with:

.gitignore

@@ -0,0 +1,101 @@
+# Dependency directory
+node_modules
+
+# Rest pulled from https://github.com/github/gitignore/blob/master/Node.gitignore
+# Logs
+logs
+*.log
+npm-debug.log*
+yarn-debug.log*
+yarn-error.log*
+lerna-debug.log*
+
+# Diagnostic reports (https://nodejs.org/api/report.html)
+report.[0-9]*.[0-9]*.[0-9]*.[0-9]*.json
+
+# Runtime data
+pids
+*.pid
+*.seed
+*.pid.lock
+
+# Directory for instrumented libs generated by jscoverage/JSCover
+lib-cov
+
+# Coverage directory used by tools like istanbul
+coverage
+*.lcov
+
+# nyc test coverage
+.nyc_output
+
+# Grunt intermediate storage (https://gruntjs.com/creating-plugins#storing-task-files)
+.grunt
+
+# Bower dependency directory (https://bower.io/)
+bower_components
+
+# node-waf configuration
+.lock-wscript
+
+# Compiled binary addons (https://nodejs.org/api/addons.html)
+build/Release
+
+# Dependency directories
+jspm_packages/
+
+# TypeScript v1 declaration files
+typings/
+
+# TypeScript cache
+*.tsbuildinfo
+
+# Optional npm cache directory
+.npm
+
+# Optional eslint cache
+.eslintcache
+
+# Optional REPL history
+.node_repl_history
+
+# Output of 'npm pack'
+*.tgz
+
+# Yarn Integrity file
+.yarn-integrity
+
+# dotenv environment variables file
+.env
+.env.test
+
+# parcel-bundler cache (https://parceljs.org/)
+.cache
+
+# next.js build output
+.next
+
+# nuxt.js build output
+.nuxt
+
+# vuepress build output
+.vuepress/dist
+
+# Serverless directories
+.serverless/
+
+# FuseBox cache
+.fusebox/
+
+# DynamoDB Local files
+.dynamodb/
+
+# OS metadata
+.DS_Store
+Thumbs.db
+
+# Ignore built ts files
+__tests__/runner/*
+lib/**/*
+
+.direnv

.prettierignore

@@ -0,0 +1,3 @@
+dist/
+lib/
+node_modules/

.prettierrc.json

@@ -0,0 +1 @@
+{}

README.md

@@ -3,9 +3,9 @@
 This repo houses a [Github Action][action] from [Determinate Systems][detsys] that performs health checks on your repos' [`flake.lock`][lock] files.
 Specifically, it wraps the [Nix Flake Checker][flake-checker] tool, which verifies that your root [Nixpkgs] inputs:
 
-* Have been updated within the last 30 days
-* Have the [`NixOS`][nixos-org] GitHub org as their owner
-* Are from a supported Git branch
+- Have been updated within the last 30 days
+- Have the [`NixOS`][nixos-org] GitHub org as their owner
+- Are from a supported Git branch
 
 Here's an example configuration that uses `flake-checker-action` as part of a broader Actions workflow involving Nix.
 
@@ -33,16 +33,16 @@ jobs:
 
 The Nix Flake Checker Action has a number of configuration parameters that you can set in the `with` block:
 
-Parameter | Description | Default
-:---------|:------------|:-------
-`flake-lock-path` | The path to the `flake.lock` file you want to check. | `flake.lock`
-`check-outdated` | Whether to check that the root Nixpkgs input is less than 30 days old. | `true`
-`check-owner` | Whether to check that the root Nixpkgs input has the `NixOS` GitHub org as its owner. | `true`
-`check-supported` | Whether to check that the root Nixpkgs input has a supported Git ref. Currently supported refs: `nixos-22.11`, `nixos-22.11-small`, `nixos-23.05`, `nixos-23.05-small`, `nixos-unstable`, `nixos-unstable-small`, `nixpkgs-22.11-darwin`, `nixpkgs-23.05-darwin`, `nixpkgs-unstable`. | `true`
-`nixpkgs-keys` | The names of the Nixpkgs inputs you want to check. By default the checker only checks the `nixpkgs` but you can specify multiple names as a comma-separated list, such as `nixpkgs,nixpkgs-macos,nixpkgs-unstable`. | `nixpkgs`
-`ignore-missing-flake-lock` | Whether to ignore a missing `flake.lock` file, where the path to the file is the value of `flake-lock-path` parameter. If set to `false` (the default is `true`), the Action throws an error and the job fails if the lockfile is missing. | `true`
-`fail-mode` | Fail with an exit code of 1 if any issues are encountered. | `false`
-`send-statistics` | Anonymously report the number of issues detected by the flake checker. This reporting helps measure the effectiveness of the flake checker. Set to `false` to disable. | `true`
+| Parameter                   | Description                                                                                                                                                                                                                                                                           | Default      |
+| :-------------------------- | :------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ | :----------- |
+| `flake-lock-path`           | The path to the `flake.lock` file you want to check.                                                                                                                                                                                                                                  | `flake.lock` |
+| `check-outdated`            | Whether to check that the root Nixpkgs input is less than 30 days old.                                                                                                                                                                                                                | `true`       |
+| `check-owner`               | Whether to check that the root Nixpkgs input has the `NixOS` GitHub org as its owner.                                                                                                                                                                                                 | `true`       |
+| `check-supported`           | Whether to check that the root Nixpkgs input has a supported Git ref. Currently supported refs: `nixos-22.11`, `nixos-22.11-small`, `nixos-23.05`, `nixos-23.05-small`, `nixos-unstable`, `nixos-unstable-small`, `nixpkgs-22.11-darwin`, `nixpkgs-23.05-darwin`, `nixpkgs-unstable`. | `true`       |
+| `nixpkgs-keys`              | The names of the Nixpkgs inputs you want to check. By default the checker only checks the `nixpkgs` but you can specify multiple names as a comma-separated list, such as `nixpkgs,nixpkgs-macos,nixpkgs-unstable`.                                                                   | `nixpkgs`    |
+| `ignore-missing-flake-lock` | Whether to ignore a missing `flake.lock` file, where the path to the file is the value of `flake-lock-path` parameter. If set to `false` (the default is `true`), the Action throws an error and the job fails if the lockfile is missing.                                            | `true`       |
+| `fail-mode`                 | Fail with an exit code of 1 if any issues are encountered.                                                                                                                                                                                                                            | `false`      |
+| `send-statistics`           | Anonymously report the number of issues detected by the flake checker. This reporting helps measure the effectiveness of the flake checker. Set to `false` to disable.                                                                                                                | `true`       |
 
 Here's an example non-default configuration:
 
@@ -62,4 +62,3 @@ Here's an example non-default configuration:
 [lock]: https://zero-to-nix.com/concepts/flakes#lockfile
 [nixos-org]: https://github.com/NixOS
 [nixpkgs]: https://github.com/NixOS/nixpkgs
-

action.yml

@@ -44,50 +44,5 @@ inputs:
       measure (and thereby improve) the effectiveness of the checker. Set to `false` to disable.
     default: true
 runs:
-  using: composite
-  steps:
-    - name: Install the flake checker
-      shell: bash
-      run: |
-        set -eu
-
-        curl \
-          --connect-timeout 5 \
-          --retry 5 \
-          --retry-connrefused \
-          --proto '=https' \
-          --tlsv1.2 \
-          -fsLS \
-          https://install.determinate.systems/flake-checker/stable/$RUNNER_ARCH-$RUNNER_OS > "$RUNNER_TEMP/flake-checker"
-
-        chmod +x "$RUNNER_TEMP/flake-checker"
-
-        export NIX_FLAKE_CHECKER_FLAKE_LOCK_PATH="${{ inputs.flake-lock-path }}"
-
-        export NIX_FLAKE_CHECKER_NIXPKGS_KEYS="${{ inputs.nixpkgs-keys }}"
-
-        if [ "${{ inputs.send-statistics }}" == "false" ]; then
-          export NIX_FLAKE_CHECKER_NO_TELEMETRY="false"
-        fi
-
-        if [ "${{ inputs.check-outdated }}" == "false" ]; then
-          export NIX_FLAKE_CHECKER_CHECK_OUTDATED="false"
-        fi
-
-        if [ "${{ inputs.check-owner }}" == "false" ]; then
-          export NIX_FLAKE_CHECKER_CHECK_OWNER="false"
-        fi
-
-        if [ "${{ inputs.check-supported }}" == "false" ]; then
-          export NIX_FLAKE_CHECKER_CHECK_SUPPORTED="false"
-        fi
-
-        if [ "${{ inputs.ignore-missing-flake-lock }}" == "false" ]; then
-          export NIX_FLAKE_CHECKER_IGNORE_MISSING_FLAKE_LOCK="false"
-        fi
-
-        if [ "${{ inputs.fail-mode }}" == "true" ]; then
-          export NIX_FLAKE_CHECKER_FAIL_MODE="true"
-        fi
-
-        "$RUNNER_TEMP/flake-checker"
+  using: "node20"
+  main: "dist/index.js"

dist/main.d.ts

@@ -0,0 +1 @@
+export {};

dist/main.js

@@ -0,0 +1,83 @@
+import * as actions_core from "@actions/core";
+import * as actions_exec from "@actions/exec";
+import { IdsToolbox } from "detsys-ts";
+class FlakeCheckerAction {
+    constructor() {
+        this.idslib = new IdsToolbox({
+            name: "flake-checker",
+            fetchStyle: "gh-env-style",
+        });
+        this.flake_lock_path =
+            action_input_string_or_null("flake-lock-path") || "flake.lock";
+        this.nixpkgs_keys =
+            action_input_string_or_null("nixpkgs-keys") || "nixpkgs";
+        this.check_outdated = action_input_bool("check-outdated");
+        this.check_owner = action_input_bool("check-owner");
+        this.check_supported = action_input_bool("check-supported");
+        this.ignore_missing_flake_lock = action_input_bool("ignore-missing-flake-lock");
+        this.fail_mode = action_input_bool("fail-mode");
+        this.send_statistics = action_input_bool("send-statistics");
+    }
+    async executionEnvironment() {
+        const execution_env = {};
+        execution_env.NIX_FLAKE_CHECKER_FLAKE_LOCK_PATH = this.flake_lock_path;
+        execution_env.NIX_FLAKE_CHECKER_NIXPKGS_KEYS = this.nixpkgs_keys;
+        if (!this.send_statistics) {
+            execution_env.NIX_FLAKE_CHECKER_NO_TELEMETRY = "false";
+        }
+        if (!this.check_outdated) {
+            execution_env.NIX_FLAKE_CHECKER_CHECK_OUTDATED = "false";
+        }
+        if (!this.check_owner) {
+            execution_env.NIX_FLAKE_CHECKER_CHECK_OWNER = "false";
+        }
+        if (!this.check_supported) {
+            execution_env.NIX_FLAKE_CHECKER_CHECK_SUPPORTED = "false";
+        }
+        if (!this.ignore_missing_flake_lock) {
+            execution_env.NIX_FLAKE_CHECKER_IGNORE_MISSING_FLAKE_LOCK = "false";
+        }
+        if (this.fail_mode) {
+            execution_env.NIX_FLAKE_CHECKER_FAIL_MODE = "true";
+        }
+        return execution_env;
+    }
+    async check() {
+        const binary_path = await this.idslib.fetchExecutable();
+        const execution_env = await this.executionEnvironment();
+        actions_core.debug(`Execution environment: ${JSON.stringify(execution_env, null, 4)}`);
+        const exit_code = await actions_exec.exec(binary_path, [], {
+            env: {
+                ...execution_env,
+                ...process.env, // To get $PATH, etc
+            },
+        });
+        if (exit_code !== 0) {
+            this.idslib.recordEvent("execution_failure", {
+                exit_code,
+            });
+            throw new Error(`Non-zero exit code of \`${exit_code}\` detected`);
+        }
+        return exit_code;
+    }
+}
+function action_input_string_or_null(name) {
+    const value = actions_core.getInput(name);
+    if (value === "") {
+        return null;
+    }
+    else {
+        return value;
+    }
+}
+function action_input_bool(name) {
+    return actions_core.getBooleanInput(name);
+}
+function main() {
+    const checker = new FlakeCheckerAction();
+    checker.idslib.onMain(async () => {
+        await checker.check();
+    });
+    checker.idslib.execute();
+}
+main();

dist/package.json

@@ -0,0 +1,3 @@
+{
+  "type": "module"
+}

flake.lock

@@ -1,21 +1,36 @@
 {
   "nodes": {
-    "nixpkgs": {
+    "flake-schemas": {
       "locked": {
-        "lastModified": 1696604326,
-        "narHash": "sha256-YXUNI0kLEcI5g8lqGMb0nh67fY9f2YoJsILafh6zlMo=",
-        "rev": "87828a0e03d1418e848d3dd3f3014a632e4a4f64",
-        "revCount": 533189,
+        "lastModified": 1697467827,
+        "narHash": "sha256-j8SR19V1SRysyJwpOBF4TLuAvAjF5t+gMiboN4gYQDU=",
+        "rev": "764932025c817d4e500a8d2a4d8c565563923d29",
+        "revCount": 29,
         "type": "tarball",
-        "url": "https://api.flakehub.com/f/pinned/NixOS/nixpkgs/0.1.533189%2Brev-87828a0e03d1418e848d3dd3f3014a632e4a4f64/018b0dc8-e84f-7c59-b5d6-16849c3b2074/source.tar.gz"
+        "url": "https://api.flakehub.com/f/pinned/DeterminateSystems/flake-schemas/0.1.2/018b3da8-4cc3-7fbb-8ff7-1588413c53e2/source.tar.gz"
       },
       "original": {
         "type": "tarball",
-        "url": "https://flakehub.com/f/NixOS/nixpkgs/0.1.533189.tar.gz"
+        "url": "https://flakehub.com/f/DeterminateSystems/flake-schemas/%2A.tar.gz"
+      }
+    },
+    "nixpkgs": {
+      "locked": {
+        "lastModified": 1712791164,
+        "narHash": "sha256-3sbWO1mbpWsLepZGbWaMovSO7ndZeFqDSdX0hZ9nVyw=",
+        "rev": "1042fd8b148a9105f3c0aca3a6177fd1d9360ba5",
+        "revCount": 610435,
+        "type": "tarball",
+        "url": "https://api.flakehub.com/f/pinned/NixOS/nixpkgs/0.1.610435%2Brev-1042fd8b148a9105f3c0aca3a6177fd1d9360ba5/018ed02d-7ab0-7d1c-9ebe-c075011335be/source.tar.gz"
+      },
+      "original": {
+        "type": "tarball",
+        "url": "https://flakehub.com/f/NixOS/nixpkgs/0.1.0.tar.gz"
       }
     },
     "root": {
       "inputs": {
+        "flake-schemas": "flake-schemas",
         "nixpkgs": "nixpkgs"
       }
     }

flake.nix

@@ -1,24 +1,31 @@
-# This flake.nix is only here to provide a flake.lock to check in CI
+# This flake was initially generated by fh, the CLI for FlakeHub (version 0.1.5)
 {
+  description = "Development environment for the Flake Checker action for GitHub.";
+
   inputs = {
-    nixpkgs.url = "https://flakehub.com/f/NixOS/nixpkgs/0.1.533189.tar.gz";
+    flake-schemas.url = "https://flakehub.com/f/DeterminateSystems/flake-schemas/*.tar.gz";
+    nixpkgs.url = "https://flakehub.com/f/NixOS/nixpkgs/0.1.0.tar.gz";
   };
 
-  outputs = { self, nixpkgs, ... }:
+  outputs = { self, flake-schemas, nixpkgs }:
     let
-      supportedSystems = [ "x86_64-linux" "aarch64-linux" "x86_64-darwin" "aarch64-darwin" ];
-      forAllSystems = f: nixpkgs.lib.genAttrs supportedSystems (system: f rec {
+      supportedSystems = [ "x86_64-linux" "aarch64-darwin" "aarch64-linux" "x86_64-darwin" ];
+      forEachSupportedSystem = f: nixpkgs.lib.genAttrs supportedSystems (system: f {
         pkgs = import nixpkgs { inherit system; };
       });
     in
     {
-      devShells = forAllSystems ({ pkgs }: {
-        default =
-          pkgs.mkShell {
-            packages = (with pkgs; [
-              nixpkgs-fmt
-            ]);
-          };
+      schemas = flake-schemas.schemas;
+
+      devShells = forEachSupportedSystem ({ pkgs }: {
+        default = pkgs.mkShell {
+          packages = with pkgs; [
+            nodejs_latest
+            nixpkgs-fmt
+            nodePackages_latest.pnpm
+            nodePackages_latest.typescript-language-server
+          ];
+        };
       });
     };
 }

package.json

@@ -0,0 +1,49 @@
+{
+  "name": "flake-checker-action",
+  "version": "1.0.0",
+  "description": "",
+  "main": "./dist/main.js",
+  "types": "./dist/main.d.ts",
+  "type": "module",
+  "scripts": {
+    "build": "tsc",
+    "format": "prettier --write .",
+    "lint": "eslint src/**/*.ts",
+    "package": "ncc build",
+    "all": "pnpm run format && pnpm run lint && pnpm run build && pnpm run package"
+  },
+  "repository": {
+    "type": "git",
+    "url": "git+https://github.com/DeterminateSystems/flake-checker-action.git"
+  },
+  "keywords": [],
+  "author": "",
+  "license": "MIT",
+  "bugs": {
+    "url": "https://github.com/DeterminateSystems/flake-checker-action/issues"
+  },
+  "homepage": "https://github.com/DeterminateSystems/flake-checker-action#readme",
+  "dependencies": {
+    "@actions/core": "^1.10.1",
+    "@actions/exec": "^1.1.1",
+    "@actions/github": "^5.1.1",
+    "@actions/tool-cache": "^2.0.1",
+    "detsys-ts": "github:DeterminateSystems/detsys-ts",
+    "fetch-retry": "^5.0.6",
+    "string-argv": "^0.3.2"
+  },
+  "devDependencies": {
+    "@trivago/prettier-plugin-sort-imports": "^4.3.0",
+    "@types/node": "^20.12.7",
+    "@types/uuid": "^9.0.8",
+    "@typescript-eslint/eslint-plugin": "^7.6.0",
+    "@vercel/ncc": "^0.38.1",
+    "eslint": "^8.57.0",
+    "eslint-import-resolver-typescript": "^3.6.1",
+    "eslint-plugin-github": "^4.10.2",
+    "eslint-plugin-import": "^2.29.1",
+    "eslint-plugin-prettier": "^5.1.3",
+    "prettier": "^3.2.5",
+    "typescript": "^5.4.5"
+  }
+}

src/main.ts

@@ -0,0 +1,134 @@
+import * as actions_core from "@actions/core";
+import * as actions_exec from "@actions/exec";
+import { IdsToolbox } from "detsys-ts";
+
+class FlakeCheckerAction {
+  idslib: IdsToolbox;
+  flake_lock_path: string;
+  nixpkgs_keys: string;
+  check_outdated: boolean;
+  check_owner: boolean;
+  check_supported: boolean;
+  ignore_missing_flake_lock: boolean;
+  fail_mode: boolean;
+  send_statistics: boolean;
+
+  constructor() {
+    this.idslib = new IdsToolbox({
+      name: "flake-checker",
+      fetchStyle: "gh-env-style",
+    });
+
+    this.flake_lock_path =
+      action_input_string_or_null("flake-lock-path") || "flake.lock";
+    this.nixpkgs_keys =
+      action_input_string_or_null("nixpkgs-keys") || "nixpkgs";
+
+    this.check_outdated = action_input_bool("check-outdated");
+    this.check_owner = action_input_bool("check-owner");
+    this.check_supported = action_input_bool("check-supported");
+
+    this.ignore_missing_flake_lock = action_input_bool(
+      "ignore-missing-flake-lock",
+    );
+
+    this.fail_mode = action_input_bool("fail-mode");
+    this.send_statistics = action_input_bool("send-statistics");
+  }
+
+  private async executionEnvironment(): Promise<ExecuteEnvironment> {
+    const execution_env: ExecuteEnvironment = {};
+
+    execution_env.NIX_FLAKE_CHECKER_FLAKE_LOCK_PATH = this.flake_lock_path;
+    execution_env.NIX_FLAKE_CHECKER_NIXPKGS_KEYS = this.nixpkgs_keys;
+
+    if (!this.send_statistics) {
+      execution_env.NIX_FLAKE_CHECKER_NO_TELEMETRY = "false";
+    }
+
+    if (!this.check_outdated) {
+      execution_env.NIX_FLAKE_CHECKER_CHECK_OUTDATED = "false";
+    }
+
+    if (!this.check_owner) {
+      execution_env.NIX_FLAKE_CHECKER_CHECK_OWNER = "false";
+    }
+
+    if (!this.check_supported) {
+      execution_env.NIX_FLAKE_CHECKER_CHECK_SUPPORTED = "false";
+    }
+
+    if (!this.ignore_missing_flake_lock) {
+      execution_env.NIX_FLAKE_CHECKER_IGNORE_MISSING_FLAKE_LOCK = "false";
+    }
+
+    if (this.fail_mode) {
+      execution_env.NIX_FLAKE_CHECKER_FAIL_MODE = "true";
+    }
+
+    return execution_env;
+  }
+
+  async check(): Promise<number> {
+    const binary_path = await this.idslib.fetchExecutable();
+
+    const execution_env = await this.executionEnvironment();
+    actions_core.debug(
+      `Execution environment: ${JSON.stringify(execution_env, null, 4)}`,
+    );
+
+    const exit_code = await actions_exec.exec(binary_path, [], {
+      env: {
+        ...execution_env,
+        ...process.env, // To get $PATH, etc
+      },
+    });
+
+    if (exit_code !== 0) {
+      this.idslib.recordEvent("execution_failure", {
+        exit_code,
+      });
+      throw new Error(`Non-zero exit code of \`${exit_code}\` detected`);
+    }
+
+    return exit_code;
+  }
+}
+
+type ExecuteEnvironment = {
+  // All env vars are strings, no fanciness here.
+  RUST_BACKTRACE?: string;
+  NIX_FLAKE_CHECKER_FLAKE_LOCK_PATH?: string;
+  NIX_FLAKE_CHECKER_NIXPKGS_KEYS?: string;
+  NIX_FLAKE_CHECKER_NO_TELEMETRY?: string;
+  NIX_FLAKE_CHECKER_CHECK_OUTDATED?: string;
+  NIX_FLAKE_CHECKER_CHECK_OWNER?: string;
+  NIX_FLAKE_CHECKER_CHECK_SUPPORTED?: string;
+  NIX_FLAKE_CHECKER_IGNORE_MISSING_FLAKE_LOCK?: string;
+  NIX_FLAKE_CHECKER_FAIL_MODE?: string;
+};
+
+function action_input_string_or_null(name: string): string | null {
+  const value = actions_core.getInput(name);
+  if (value === "") {
+    return null;
+  } else {
+    return value;
+  }
+}
+
+function action_input_bool(name: string): boolean {
+  return actions_core.getBooleanInput(name);
+}
+
+function main(): void {
+  const checker = new FlakeCheckerAction();
+
+  checker.idslib.onMain(async () => {
+    await checker.check();
+  });
+
+  checker.idslib.execute();
+}
+
+main();

tsconfig.json

@@ -0,0 +1,15 @@
+{
+  "compilerOptions": {
+    "target": "ES2020" /* Specify ECMAScript target version: 'ES3' (default), 'ES5', 'ES2015', 'ES2016', 'ES2017', 'ES2018', 'ES2019' or 'ESNEXT'. */,
+    "module": "Node16",
+    "moduleResolution": "NodeNext",
+    "outDir": "./dist",
+    "rootDir": "./src",
+    "strict": true /* Enable all strict type-checking options. */,
+    "noImplicitAny": true /* Raise error on expressions and declarations with an implied 'any' type. */,
+    "esModuleInterop": true /* Enables emit interoperability between CommonJS and ES Modules via creation of namespace objects for all imports. Implies 'allowSyntheticDefaultImports'. */,
+    "resolveJsonModule": true,
+    "declaration": true
+  },
+  "exclude": ["node_modules", "**/*.test.ts", "dist"]
+}