feat: add nix testing with devimint (#62)

* feat: add nix testing with devimint

* chore: update testing docs

* chore: cleanup

* feat: Add Devimint to testing harness

* feat: Add nix setup to testing workflow

* fix: readd cachix to nix workflow

* fix: workflow nix develop

* fix: remove retry logic in test workflow

* chore: changet  fedimint target

* fix: tweak test

.changeset/great-mugs-yawn.md

@@ -0,0 +1,5 @@
+---
+'@fedimint/core-web': patch
+---
+
+Added Nix devshell to run Devimint within testing suite

.envrc

@@ -0,0 +1 @@
+use flake

.github/actions/setup-nix/action.yml

@@ -0,0 +1,25 @@
+name: Setup Nix
+description: Sets up nix for running tests with devimint
+
+inputs:
+  cachix_auth_token:
+    description: 'Cachix authentication token'
+    required: true
+
+runs:
+  using: 'composite'
+  steps:
+    - name: Install Nix
+      uses: cachix/install-nix-action@V27
+      with:
+        nix_path: nixpkgs=channel:nixos-23.11
+        extra_nix_config: |
+          connect-timeout = 15
+          stalled-download-timeout = 15
+
+    - name: Setup Cachix
+      uses: cachix/cachix-action@v15
+      with:
+        name: fedimint
+        authToken: ${{ inputs.cachix_auth_token }}
+      continue-on-error: true

.github/workflows/verify.yml

@@ -63,15 +63,16 @@ jobs:
       - name: Install dependencies
         uses: ./.github/actions/install-deps
 
+      - name: Setup Nix
+        uses: ./.github/actions/setup-nix
+        with:
+          cachix_auth_token: ${{ secrets.CACHIX_AUTH_TOKEN }}
+
       - name: Setup Playwright
         run: pnpm exec playwright install
 
       - name: Run Tests
-        uses: nick-fields/retry@v3
-        with:
-          command: pnpm test
-          max_attempts: 3
-          timeout_seconds: 180
+        run: nix develop -c pnpm test
 
   build-docs:
     name: Build Docs

.gitignore

@@ -9,13 +9,7 @@ node_modules
 tsconfig.tsbuildinfo
 *.vitest-temp.json
 
-# local env files
-.env
-.env.local
-.env.development.local
-.env.test.local
-.env.production.local
-.envrc
+.direnv
 /test-results/
 /playwright-report/
 /blob-report/

docs/core/dev/testing.md

@@ -9,6 +9,36 @@ Vitest [browser mode](https://vitest.dev/guide/browser/) + playwright (provider)
 
 This framework should be suitable for all the additional libraries we have planned (e.g. react).
 
+## Nix
+
+The Fedimint Web SDK depends on several external pieces of infrastructure. In order to run high-fidelity tests, we utilize a tool from the [fedimint](https://github.com/fedimint/fedimint) repo called [Devimint](https://github.com/fedimint/fedimint/tree/master/devimint). Devimint includes several pieces of infrastructure for running a local testing environment for fedimint applications including a bitcoind node (regtest), multiple guardian servers (fedimintd), multiple lightning gateways (lnd, cln, ldk), and a faucet for minting tokens.
+
+::: warning Note
+
+Nix is NOT required to build or use the Fedimint Web SDK. It is ONLY required to run the tests.
+
+:::
+
+## Nix Installation & Setup
+
+To setup nix, use the [Determinate Nix Installer](https://github.com/DeterminateSystems/nix-installer)
+
+```sh
+# The exact version might be different.
+> nix --version
+nix (Nix) 2.9.1
+```
+
+Next, [install direnv](https://direnv.net/docs/installation.html) and run the following command to initialize direnv in your shell:
+
+```sh
+direnv allow
+```
+
+::: tip
+This takes a really long time to run for the first time. All future runs will be relatively quick.
+:::
+
 ## Usage
 
 ```bash