Add CI workflow to check general file formatting

On every push, pull request, and periodically, check whether the repository's files are formatted according to
.editorconfig.

.ecrc

@@ -0,0 +1,14 @@
+{
+  "Exclude": [
+    "^\\.git[/\\\\]",
+    "^\\.licenses[/\\\\]",
+    ".pytest_cache[/\\\\]",
+    "__pycache__[/\\\\]",
+    "node_modules[/\\\\]",
+    "^LICENSE\\.txt$",
+    "^poetry\\.lock$",
+    "\\.py$",
+    "^compilesketches[/\\\\]tests[/\\\\]testdata[/\\\\]test_get_warning_count_from_output[/\\\\]has-warnings\\.txt$",
+    "^compilesketches[/\\\\]tests[/\\\\]testdata[/\\\\]test_get_warning_count_from_output[/\\\\]no-warnings\\.txt$"
+  ]
+}

.editorconfig

@@ -0,0 +1,60 @@
+# Source: https://github.com/arduino/tooling-project-assets/blob/main/workflow-templates/assets/general/.editorconfig
+# See: https://editorconfig.org/
+# The formatting style defined in this file is the official standardized style to be used in all Arduino Tooling
+# projects and should not be modified.
+# Note: indent style for each file type is defined even when it matches the universal config in order to make it clear
+# that this type has an official style.
+
+[*]
+charset = utf-8
+end_of_line = lf
+indent_size = 2
+indent_style = space
+insert_final_newline = true
+trim_trailing_whitespace = true
+
+[*.{adoc,asc,asciidoc}]
+indent_size = 2
+indent_style = space
+
+[*.{bash,sh}]
+indent_size = 2
+indent_style = space
+
+[*.{c,cc,cp,cpp,cxx,h,hh,hpp,hxx,ii,inl,ino,ixx,pde,tpl,tpp,txx}]
+indent_size = 2
+indent_style = space
+
+[*.{go,mod}]
+indent_style = tab
+
+[*.java]
+indent_size = 2
+indent_style = space
+
+[*.{js,jsx,json,jsonc,json5,ts,tsx}]
+indent_size = 2
+indent_style = space
+
+[*.{md,mdx,mkdn,mdown,markdown}]
+indent_size = unset
+indent_style = space
+
+[*.proto]
+indent_size = 2
+indent_style = space
+
+[*.py]
+indent_size = 4
+indent_style = space
+
+[*.svg]
+indent_size = 2
+indent_style = space
+
+[*.{yaml,yml}]
+indent_size = 2
+indent_style = space
+
+[{.gitconfig,.gitmodules}]
+indent_style = tab

.github/workflows/check-general-formatting-task.yml

@@ -0,0 +1,79 @@
+# Source: https://github.com/arduino/tooling-project-assets/blob/main/workflow-templates/check-general-formatting-task.md
+name: Check General Formatting
+
+# See: https://docs.github.com/actions/using-workflows/events-that-trigger-workflows
+on:
+  create:
+  push:
+  pull_request:
+  schedule:
+    # Run every Tuesday at 8 AM UTC to catch breakage caused by changes to tools.
+    - cron: "0 8 * * TUE"
+  workflow_dispatch:
+  repository_dispatch:
+
+jobs:
+  run-determination:
+    runs-on: ubuntu-latest
+    outputs:
+      result: ${{ steps.determination.outputs.result }}
+    steps:
+      - name: Determine if the rest of the workflow should run
+        id: determination
+        run: |
+          RELEASE_BRANCH_REGEX="refs/heads/[0-9]+.[0-9]+.x"
+          # The `create` event trigger doesn't support `branches` filters, so it's necessary to use Bash instead.
+          if [[
+            "${{ github.event_name }}" != "create" ||
+            "${{ github.ref }}" =~ $RELEASE_BRANCH_REGEX
+          ]]; then
+            # Run the other jobs.
+            RESULT="true"
+          else
+            # There is no need to run the other jobs.
+            RESULT="false"
+          fi
+
+          echo "result=$RESULT" >> $GITHUB_OUTPUT
+
+  check:
+    needs: run-determination
+    if: needs.run-determination.outputs.result == 'true'
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Set environment variables
+        run: |
+          # See: https://docs.github.com/actions/using-workflows/workflow-commands-for-github-actions#setting-an-environment-variable
+          echo "EC_INSTALL_PATH=${{ runner.temp }}/editorconfig-checker" >> "$GITHUB_ENV"
+
+      - name: Checkout repository
+        uses: actions/checkout@v3
+
+      - name: Install Task
+        uses: arduino/setup-task@v1
+        with:
+          repo-token: ${{ secrets.GITHUB_TOKEN }}
+          version: 3.x
+
+      - name: Download latest editorconfig-checker release binary package
+        id: download
+        uses: MrOctopus/[email protected]
+        with:
+          repository: editorconfig-checker/editorconfig-checker
+          excludes: prerelease, draft
+          asset: linux-amd64.tar.gz
+          target: ${{ env.EC_INSTALL_PATH }}
+
+      - name: Install editorconfig-checker
+        run: |
+          cd "${{ env.EC_INSTALL_PATH }}"
+          tar --extract --file="${{ steps.download.outputs.name }}"
+          # Give the binary a standard name
+          mv "${{ env.EC_INSTALL_PATH }}/bin/ec-linux-amd64" "${{ env.EC_INSTALL_PATH }}/bin/ec"
+          # Add installation to PATH:
+          # See: https://docs.github.com/actions/using-workflows/workflow-commands-for-github-actions#adding-a-system-path
+          echo "${{ env.EC_INSTALL_PATH }}/bin" >> "$GITHUB_PATH"
+
+      - name: Check formatting
+        run: task --silent general:check-formatting

README.md

@@ -2,6 +2,7 @@
 
 [![Check Action Metadata status](https://github.com/arduino/compile-sketches/actions/workflows/check-action-metadata-task.yml/badge.svg)](https://github.com/arduino/compile-sketches/actions/workflows/check-action-metadata-task.yml)
 [![Check Files status](https://github.com/arduino/compile-sketches/actions/workflows/check-files-task.yml/badge.svg)](https://github.com/arduino/compile-sketches/actions/workflows/check-files-task.yml)
+[![Check General Formatting status](https://github.com/arduino/compile-sketches/actions/workflows/check-general-formatting-task.yml/badge.svg)](https://github.com/arduino/compile-sketches/actions/workflows/check-general-formatting-task.yml)
 [![Check Python status](https://github.com/arduino/compile-sketches/actions/workflows/check-python-task.yml/badge.svg)](https://github.com/arduino/compile-sketches/actions/workflows/check-python-task.yml)
 [![Spell Check status](https://github.com/arduino/compile-sketches/actions/workflows/spell-check-task.yml/badge.svg)](https://github.com/arduino/compile-sketches/actions/workflows/spell-check-task.yml)
 [![Sync Labels status](https://github.com/arduino/compile-sketches/actions/workflows/sync-labels-npm.yml/badge.svg)](https://github.com/arduino/compile-sketches/actions/workflows/sync-labels-npm.yml)

Taskfile.yml

@@ -9,6 +9,7 @@ tasks:
     desc: Check for problems with the project
     deps:
       - task: action:validate
+      - task: general:check-formatting
       - task: general:check-spelling
       - task: python:lint
       - task: python:test
@@ -111,6 +112,18 @@ tasks:
           false
         }
 
+  # Source: https://github.com/arduino/tooling-project-assets/blob/main/workflow-templates/assets/check-general-formatting-task/Taskfile.yml
+  general:check-formatting:
+    desc: Check basic formatting style of all files
+    cmds:
+      - |
+        if ! which ec &>/dev/null; then
+          echo "ec not found or not in PATH."
+          echo "Please install: https://github.com/editorconfig-checker/editorconfig-checker#installation"
+          exit 1
+        fi
+      - ec
+
   # Source: https://github.com/arduino/tooling-project-assets/blob/main/workflow-templates/assets/spell-check-task/Taskfile.yml
   general:check-spelling:
     desc: Check for commonly misspelled words