!ci: add ci for unit tests (#96)

* add ci tests

* Reduce test processors

.github/mergify.yml

@@ -0,0 +1,20 @@
+queue_rules:
+  - name: default
+    conditions:
+      - "#approved-reviews-by>=1"
+      - base=main
+      - label=automerge
+
+pull_request_rules:
+  - name: automerge to main with label automerge and branch protection passing
+    conditions:
+      - "#approved-reviews-by>=1"
+      - base=main
+      - label=automerge
+    actions:
+      queue:
+        name: default
+        method: merge
+        commit_message_template: |
+          {{ title }} (#{{ number }})
+          {{ body }}

.github/workflows/test.yml

@@ -0,0 +1,60 @@
+name: Tests / Code Coverage
+#  Tests / Code Coverage workflow runs unit tests and uploads a code coverage report
+#  This workflow is run on pushes to main & every Pull Requests where a .go, .mod, .sum have been changed
+on:
+  pull_request:
+  push:
+    branches:
+      - main
+
+jobs:
+
+  split-test-files:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - name: Create a file with all the pkgs
+        run: go list ./... | grep -v e2e > pkgs.txt
+      - name: Split pkgs into 2 files
+        run: split -d -n l/2 pkgs.txt pkgs.txt.part.
+      # cache multiple
+      - uses: actions/upload-artifact@v4
+        with:
+          name: '${{ github.sha }}-00'
+          path: ./pkgs.txt.part.00
+      - uses: actions/upload-artifact@v4
+        with:
+          name: '${{ github.sha }}-01'
+          path: ./pkgs.txt.part.01
+
+  tests:
+    runs-on: ubuntu-latest
+    needs: split-test-files
+    strategy:
+      fail-fast: false
+      matrix:
+        part: ['00', '01']
+    steps:
+      - uses: actions/checkout@v4
+      - uses: actions/setup-go@v5
+        with:
+          go-version: '1.19'
+      - uses: technote-space/get-diff-action@v6.1.2
+        with:
+          PATTERNS: |
+            **/**.go
+            go.mod
+            go.sum
+      - uses: actions/download-artifact@v4
+        with:
+          name: '${{ github.sha }}-${{ matrix.part }}'
+        if: env.GIT_DIFF
+      - name: test & coverage report creation
+        run: |
+          cat pkgs.txt.part.${{ matrix.part }} | xargs go test -mod=readonly -timeout 30m -coverprofile=${{ matrix.part }}profile.out -covermode=atomic -tags='ledger test_ledger_mock'
+        if: env.GIT_DIFF
+      - uses: actions/upload-artifact@v4
+        with:
+          name: '${{ github.sha }}-${{ matrix.part }}-coverage'
+          path: ./${{ matrix.part }}profile.out
+