add wrapper to expose stdout, stderr, and exitcode

Closes #173

.github/workflows/test.yml

@@ -45,7 +45,7 @@ jobs:
 
   integration:
     name: Integration test
-    
+
     strategy:
       matrix:
         os:
@@ -98,3 +98,29 @@ jobs:
         tflint_version: ${{ matrix.tflint_version }}
     - name: Run
       run: tflint -f compact --force
+
+  integration-wrapper:
+    name: 'Integration test (tflint_version: ${{ matrix.tflint_version }})'
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        tflint_version: [ 'v0.26.0', latest ]
+
+    steps:
+      - uses: actions/checkout@v3
+      - name: Use Action
+        uses: ./
+        with:
+          tflint_version: ${{ matrix.tflint_version }}
+          tflint_wrapper: true
+      - name: Run
+        id: tflint
+        run: tflint -f compact --force
+      - name: Verify Exit Code Output
+        run: |
+          if [[ ${{ steps.tflint.outputs.exitcode }} -ne 0 ]]; then
+            echo "TFLint Exit Code not captured."
+            exit 1
+          else
+            echo "TFLint Exit Code captured."
+          fi

.gitignore

@@ -66,3 +66,6 @@ typings/
 # next.js build output
 .next
 
+# ./wrapper/dist gets included in top-level ./dist
+wrapper/dist
+

README.md

@@ -19,9 +19,19 @@ Used to authenticate requests to the GitHub API to obtain release data from the
 
 Default: `${{ github.token }}`
 
+### `tflint_wrapper`
+
+Installs a wrapper script to wrap subsequent calls to `tflint` and expose `stdout`, `stderr`, and `exitcode` outputs.
+
+Default: `"false"`
+
 ## Outputs
 
-The action does not have any output.
+The following outputs are available when the `tflint_wrapper` input is enabled:
+
+- `stdout` - The output (stdout) produced by the tflint command.
+- `stderr` - The error output (stdout) produced by the tflint command.
+- `exitcode` - The exit code produced by the tflint command.
 
 ## Usage
 
@@ -98,6 +108,21 @@ or specify it explicitly as
 - run: tflint -f compact
 ```
 
+### Wrapper
+
+```yaml
+- uses: terraform-linters/setup-tflint@v3
+  with:
+    tflint_wrapper: true
+
+- id: tflint
+  run: tflint -f compact
+
+- run: echo ${{ steps.tflint.outputs.stdout }}
+- run: echo ${{ steps.tflint.outputs.stderr }}
+- run: echo ${{ steps.tflint.outputs.exitcode }}
+```
+
 ### Checks
 
 This action supports [Problem Matchers](https://github.com/actions/toolkit/blob/main/docs/problem-matchers.md) for `--format compact`. You can see annotations in pull requests when TFLint prints issues with the `compact` format.

action.yml

@@ -9,6 +9,17 @@ inputs:
     description: GitHub token - used when getting the latest version of tflint
     required: false
     default: ${{ github.token }}
+  tflint_wrapper:
+    description: Installs a wrapper script to wrap subsequent calls to `tflint` and expose `stdout`, `stderr`, and `exitcode` outputs
+    default: 'false'
+    required: false
+outputs:
+  stdout:
+    description: The output (stdout) produced by the tflint command. Only available if `tflint_wrapper` is set to `true`.
+  stderr:
+    description: The error output (stderr) produced by the tflint command. Only available if `tflint_wrapper` is set to `true`.
+  exitcode:
+    description: The exit code produced by the tflint command. Only available if `tflint_wrapper` is set to `true`.
 runs:
   using: 'node16'
   main: 'dist/index.js'