Add workflow for checking the script

This set of checks will allow you to fully test the script by fixing
its behavior similar to the tests. This will help to avoid errors like
in #8

.github/workflows/shell.yml

@@ -8,12 +8,69 @@ on:
   workflow_dispatch:
 
 jobs:
-  check-shell-scripts:
-    name: Check
+  lint-shell-scripts:
+    name: Lint
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4
-      - name: Run shfmt and shellcheck
-        uses: luizm/[email protected]
-        env:
-          SHFMT_OPTS: -d -s -w -i 4 -ln bash
+    - uses: actions/checkout@v4
+    - name: Run shfmt and shellcheck
+      uses: luizm/[email protected]
+      env:
+        SHFMT_OPTS: -d -s -w -i 4 -ln bash
+
+  check-script-logic:
+    name: Check pkg:${{ matrix.pkg }} os:${{ matrix.os }}
+    runs-on: '${{ matrix.os }}'
+    strategy:
+      matrix:
+        os:
+        - ubuntu-latest
+        - macos-latest
+        pkg:
+        - all
+        - go
+      fail-fast: false
+    steps:
+    - uses: actions/checkout@v4
+
+    - name: Set up Go
+      uses: actions/setup-go@v5
+      with:
+        go-version: '1.23.1'
+        cache: false
+
+    - name: Configure test repository
+      run: |
+        git clone https://github.com/xorcare/tornado
+        cd tornado
+        git config user.email "[email protected]"
+        git config user.name "Your Name"
+
+    - name: Setup git user
+      working-directory: tornado
+      run: |
+        git config user.email "[email protected]"
+        git config user.name "Your Name"
+
+    - name: Test help flags
+      working-directory: tornado
+      run: |
+        ../go-mod-bump.sh -h
+        ../go-mod-bump.sh -help
+
+    - name: Default exit code must be zero
+      working-directory: tornado
+      run: |
+        ../go-mod-bump.sh
+
+    - name: Test bump '${{ matrix.pkg }}'
+      working-directory: tornado
+      run: |
+        git checkout --quiet 029fe5d254ab71c1e72444adcda808f5a494084d
+        ../go-mod-bump.sh ${{ matrix.pkg }}
+        commit_count=$(git rev-list --count HEAD ^029fe5d254ab71c1e72444adcda808f5a494084d)
+        if [[ "$commit_count" == 0 ]]; then
+          echo "ERROR: No changes have been detected, but they must be exist"
+          exit 1
+        fi
+        git diff 029fe5d254ab71c1e72444adcda808f5a494084d