Add a pre commit hook to lint code

This uses pre-commit [1] to check patches are well formed and run
several linters on them. We currently do some boring things (check files
are syntactically valid) as well as some project-specific ones:
 - Run illuaminate on the Lua files
 - Run checkstyle on Java

[1]: https://pre-commit.com/

.editorconfig

@@ -16,6 +16,3 @@ indent_size = 2
 
 [*.yml]
 indent_size = 2
-
-[*.properties]
-insert_final_newline = false

.github/workflows/main-ci.yml

@@ -23,10 +23,15 @@ jobs:
         restore-keys: |
           ${{ runner.os }}-gradle-
 
+    - name: Disable Gradle daemon
+      run: |
+        mkdir -p ~/.gradle
+        echo "org.gradle.daemon=false" >> ~/.gradle/gradle.properties
+
     - name: Build with Gradle
       run: |
-        ./gradlew assemble --no-daemon || ./gradlew assemble --no-daemon
-        ./gradlew downloadAssets --no-daemon || ./gradlew downloadAssets --no-daemon
+        ./gradlew assemble || ./gradlew assemble
+        ./gradlew downloadAssets || ./gradlew downloadAssets
         ./gradlew build
 
     - name: Upload Jar
@@ -39,15 +44,14 @@ jobs:
       run: bash <(curl -s https://codecov.io/bash)
       continue-on-error: true
 
-    - name: Generate Java documentation stubs
-      run: ./gradlew luaJavadoc --no-daemon
-
-    - name: Lint Lua code
+    - name: Cache pre-commit
+      uses: actions/cache@v2
+      with:
+        path: ~/.cache/pre-commit
+        key: ${{ runner.os }}-pre-commit-${{ hashFiles('config/pre-commit/config.yml') }}
+        restore-keys: |
+          ${{ runner.os }}-pre-commit-
+    - name: Run linters
       run: |
-        test -d bin || mkdir bin
-        test -f bin/illuaminate || wget -q -Obin/illuaminate https://squiddev.cc/illuaminate/linux-x86-64/illuaminate
-        chmod +x bin/illuaminate
-        bin/illuaminate lint
-
-    - name: Check whitespace
-      run: python3 tools/check-lines.py
+        pip install pre-commit
+        pre-commit run --config config/pre-commit/config.yml --show-diff-on-failure --all --color=always

CONTRIBUTING.md

@@ -65,7 +65,7 @@ Gradle should be your entrypoint to building most documentation. There's two tas
 
 #### Writing documentation
 illuaminate's documentation system is not currently documented (somewhat ironic), but is _largely_ the same as
-[ldoc][ldoc]. Documentation comments are written in Markdown, 
+[ldoc][ldoc]. Documentation comments are written in Markdown,
 
 Our markdown engine does _not_ support GitHub flavoured markdown, and so does not support all the features one might
 expect (such as tables). It is very much recommended that you build and preview the docs locally first.
@@ -77,18 +77,18 @@ entire test suite (and some additional bits of verification).
 Before we get into writing tests, it's worth mentioning the various test suites that CC: Tweaked has:
  - "Core" Java (`./src/test/java`): These test core bits of the mod which don't require any Minecraft interaction.
    This includes the `@LuaFunction` system, file system code, etc...
-   
+
    These tests are run by `./gradlew test`.
 
  - CraftOS (`./src/test/resources/test-rom/`): These tests are written in Lua, and ensure the Lua environment, libraries
    and programs work as expected. These are (generally) written to be able to be run on emulators too, to provide some
    sort of compliance test.
-   
+
    These tests are run by the '"Core" Java' test suite, and so are also run with `./gradlew test`.
 
  - In-game (`./src/test/java/dan200/computercraft/ingame/`): These tests are run on an actual Minecraft server, using
    [the same system Mojang do][mc-test]. The aim of these is to test in-game behaviour of blocks and peripherals.
-   
+
    These are run by `./gradlew testInGame`.
 
 ## CraftOS tests

LICENSE

@@ -19,14 +19,14 @@ Mod: The mod code designated by the present license, in source form, binary
 form, as obtained standalone, as part of a wider distribution or resulting from
 the compilation of the original or modified sources.
 
-Dependency: Code required for the mod to work properly. This includes 
+Dependency: Code required for the mod to work properly. This includes
 dependencies required to compile the code as well as any file or modification
 that is explicitly or implicitly required for the mod to be working.
 
 1. Scope
 --------
 
-The present license is granted to any user of the mod. As a prerequisite, 
+The present license is granted to any user of the mod. As a prerequisite,
 a user must own a legally acquired copy of Minecraft
 
 2. Liability
@@ -41,13 +41,13 @@ or misuse of this mod fall on the user.
 3. Play rights
 --------------
 
-The user is allowed to install this mod on a Minecraft client or server and to play 
+The user is allowed to install this mod on a Minecraft client or server and to play
 without restriction.
 
 4. Modification rights
 ----------------------
 
-The user has the right to decompile the source code, look at either the 
+The user has the right to decompile the source code, look at either the
 decompiled version or the original source code, and to modify it.
 
 5. Distribution of original or modified copy rights
@@ -61,10 +61,10 @@ include:
    - patch to its source or binary files
    - any copy of a portion of its binary source files
 
-The user is allowed to redistribute this mod partially, in totality, or 
+The user is allowed to redistribute this mod partially, in totality, or
 included in a distribution.
 
-When distributing binary files, the user must provide means to obtain its 
+When distributing binary files, the user must provide means to obtain its
 entire set of sources or modified sources at no cost.
 
 All distributions of this mod must remain licensed under the CCPL.
@@ -92,7 +92,7 @@ must be made available at no cost and remain licensed under the CCPL.
 ---------------
 
 If you choose to contribute code or assets to be included in this mod, you
-agree that, if added to to the main repository at 
+agree that, if added to to the main repository at
 https://github.com/dan200/ComputerCraft, your contributions will be covered by
 this license, and that Daniel Ratcliffe will retain the right to re-license the
 mod, including your contributions, in part or in whole, under other licenses.

config/idea/codeInspectionSettings.xml

@@ -2488,4 +2488,4 @@
       </option>
     </inspection_tool>
   </profile>
-</component>
+</component>

config/idea/codeStyleSettings.xml

@@ -58,4 +58,4 @@
       <option name="CONTINUATION_INDENT_SIZE" value="4" />
     </indentOptions>
   </codeStyleSettings>
-</code_scheme>
+</code_scheme>

config/pre-commit/config.yml

@@ -0,0 +1,48 @@
+# See https://pre-commit.com for more information
+# See https://pre-commit.com/hooks.html for more hooks
+repos:
+- repo: https://github.com/pre-commit/pre-commit-hooks
+  rev: v3.2.0
+  hooks:
+  - id: trailing-whitespace
+  - id: end-of-file-fixer
+  - id: check-merge-conflict
+
+  # Quick syntax checkers
+  - id: check-xml
+  - id: check-yaml
+  - id: check-toml
+  - id: check-json
+    exclude: "tsconfig\\.json$"
+
+- repo: https://github.com/editorconfig-checker/editorconfig-checker.python
+  rev: 2.3.5
+  hooks:
+  - id: editorconfig-checker
+    args: ['-disable-indentation']
+    exclude: "^(.*\\.(bat)|LICENSE)$"
+
+- repo: local
+  hooks:
+  - id: checkstyle
+    name: Check Java codestyle
+    files: ".*\\.java$"
+    language: system
+    entry: ./gradlew checkstyleMain checkstyleTest
+    pass_filenames: false
+    require_serial: true
+  - id: illuaminate
+    name: Check Lua code
+    files: ".*\\.(lua|java|md)"
+    language: script
+    entry: config/pre-commit/illuaminate-lint.sh
+    pass_filenames: false
+    require_serial: true
+
+exclude: |
+  (?x)^(
+    src/generated|
+    src/test/resources/test-rom/data/json-parsing/|
+    src/test/server-files/|
+    config/idea/
+  )

config/pre-commit/illuaminate-lint.sh

@@ -0,0 +1,9 @@
+#!/usr/bin/env sh
+set -e
+
+test -d bin || mkdir bin
+test -f bin/illuaminate || curl -s -obin/illuaminate https://squiddev.cc/illuaminate/linux-x86-64/illuaminate
+chmod +x bin/illuaminate
+
+./gradlew luaJavadoc
+bin/illuaminate lint

doc/events/key.md

@@ -20,7 +20,7 @@ Prints each key when the user presses it, and if the key is being held.
 
 ```lua
 while true do
-  local event, key, is_held = os.pullEvent("key")  
+  local event, key, is_held = os.pullEvent("key")
   print(("%s held=%s"):format(keys.getName(key), is_held))
 end
 ```

src/main/resources/data/computercraft/lua/rom/apis/colours.lua

@@ -5,7 +5,7 @@
 
 local colours = _ENV
 for k, v in pairs(colors) do
-	colours[k] = v
+    colours[k] = v
 end
 
 --- Grey. Written as `7` in paint files and @{term.blit}, has a default

src/main/resources/data/computercraft/lua/rom/autorun/.ignoreme

@@ -1,4 +1,4 @@
 --[[
 Alright then, don't ignore me. This file is to ensure the existence of the "autorun" folder, files placed in this folder
 using resource packs will always run when computers startup.
-]]
+]]

tools/check-lines.py

@@ -1,45 +0,0 @@
-import pathlib, sys
-
-problems = False
-
-# Skip images and files without extensions
-exclude = [
-    "*.png",
-    "**/data/json-parsing/*.json",
-    "**/computers/ids.json",
-]
-
-for path in pathlib.Path("src").glob("**/*"):
-    # Ideally we'd use generated as a glob, but .match("generated/**/*.json") doesn't work!
-    if path.is_dir() or path.suffix == "" or any(path.match(x) for x in exclude) or path.parts[1] == "generated":
-        continue
-
-    with path.open(encoding="utf-8") as file:
-        has_dos, has_trailing, first, count = False, False, 0, True
-        for i, line in enumerate(file):
-            if first:
-                first = False
-                if line.strip() == "":
-                    print("%s has empty first line" % path)
-
-            if len(line) >= 2 and line[-2] == "\r" and line[-1] == "\n" and not has_dos:
-                print("%s has contains '\\r\\n' on line %d" % (path, i + 1))
-                problems = has_dos = True
-
-            if len(line) >= 2 and line[-2] in " \t" and line[-1] == "\n" and not has_trailing:
-                print("%s has trailing whitespace on line %d" % (path, i + 1))
-                problems = has_trailing = True
-
-            if len(line) == 0 or line[-1] != "\n":
-                count = 0
-            elif line.strip() == "":
-                count += 1
-            else:
-                count = 1
-
-        if count != 1:
-            print("%s should have 1 trailing lines, but has %d" % (path, count))
-            problems = True
-
-if problems:
-    sys.exit(1)