Add problem matchers for Github actions

- Add a basic problem matcher for illuaminate errors.
 - Add a script (tools/parse-reports.py) which parses the XML reports
   generated by checkstyle and junit, extracts source locations, and
   emits them in a manner which can be consumed by another set of
   matchers.

This should make it a little easier to see problems for folks who just
rely on CI to test things (though also, please don't do this if you can
help it).

.github/matchers/checkstyle.json

@@ -0,0 +1,17 @@
+{
+    "problemMatcher": [
+        {
+            "owner": "checkstyle",
+            "pattern": [
+                {
+                    "regexp": "^([a-z]+) ([\\w./-]+):(\\d+):(\\d+): (.*)$",
+                    "severity": 1,
+                    "file": 2,
+                    "line": 3,
+                    "column": 4,
+                    "message": 5
+                }
+            ]
+        }
+    ]
+}

.github/matchers/illuaminate.json

@@ -0,0 +1,18 @@
+{
+    "problemMatcher": [
+        {
+            "owner": "illuaminate",
+            "severity": "warning",
+            "pattern": [
+                {
+                    "regexp": "^([\\w./-]+):\\[(\\d+):(\\d+)\\-(?:\\d+):(?:\\d+)\\]: (.*) \\[([a-z:-]+)\\]$",
+                    "file": 1,
+                    "line": 2,
+                    "column": 3,
+                    "message": 4,
+                    "code": 5
+                }
+            ]
+        }
+    ]
+}

.github/matchers/junit.json

@@ -0,0 +1,15 @@
+{
+    "problemMatcher": [
+        {
+            "owner": "junit",
+            "pattern": [
+                {
+                    "regexp": "^## ([\\w./-]+):(\\d+): (.*)$",
+                    "file": 1,
+                    "line": 2,
+                    "message": 3
+                }
+            ]
+        }
+    ]
+}

.github/workflows/main-ci.yml

@@ -41,8 +41,11 @@ jobs:
         path: build/libs
 
     - name: Upload Coverage
-      run: bash <(curl -s https://codecov.io/bash)
-      continue-on-error: true
+      uses: codecov/codecov-action@v1
+
+    - name: Parse test reports
+      run: ./tools/parse-reports.py
+      if: ${{ failure() }}
 
     - name: Cache pre-commit
       uses: actions/cache@v2
@@ -51,6 +54,7 @@ jobs:
         key: ${{ runner.os }}-pre-commit-${{ hashFiles('config/pre-commit/config.yml') }}
         restore-keys: |
           ${{ runner.os }}-pre-commit-
+
     - name: Run linters
       run: |
         pip install pre-commit

config/pre-commit/illuaminate-lint.sh

@@ -5,5 +5,12 @@ 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
 
+if [ -n ${GITHUB_ACTIONS+x} ]; then
+    # Register a problem matcher (see https://github.com/actions/toolkit/blob/master/docs/problem-matchers.md)
+    # for illuaminate.
+    echo "::add-matcher::.github/matchers/illuaminate.json"
+    trap 'echo "::remove-matcher owner=illuaminate::"' EXIT
+fi
+
 ./gradlew luaJavadoc
 bin/illuaminate lint

tools/parse-reports.py

@@ -0,0 +1,114 @@
+#!/usr/bin/env python3
+"""
+Parse reports generated by Gradle and convert them into GitHub annotations.
+
+See https://github.com/actions/toolkit/blob/master/docs/problem-matchers.md and
+https://github.com/actions/toolkit/blob/master/docs/commands.md.
+"""
+
+from typing import Optional, Tuple
+import pathlib
+import xml.etree.ElementTree as ET
+import re
+import os.path
+
+
+LUA_ERROR_LOCATION = re.compile(r"^\s+(/[\w./-]+):(\d+):", re.MULTILINE)
+JAVA_ERROR_LOCATION = re.compile(r"^\tat ([\w.]+)\.[\w]+\([\w.]+:(\d+)\)$", re.MULTILINE)
+ERROR_MESSAGE = re.compile(r"(.*)\nstack traceback:", re.DOTALL)
+
+SPACES = re.compile(r"\s+")
+
+SOURCE_LOCATIONS = [
+    "src/main/java",
+    "src/main/resources/data/computercraft/lua",
+    "src/test/java",
+    "src/test/resources",
+]
+
+
+def find_file(path: str) -> Optional[str]:
+    while len(path) > 0 and path[0] == '/':
+        path = path[1:]
+
+    for source_dir in SOURCE_LOCATIONS:
+        child_path = os.path.join(source_dir, path)
+        if os.path.exists(child_path):
+            return child_path
+
+    return None
+
+
+def find_location(message: str) -> Optional[Tuple[str, str]]:
+    location = LUA_ERROR_LOCATION.search(message)
+    if location:
+        file = find_file(location[1])
+        if file:
+            return file, location[2]
+
+    for location in JAVA_ERROR_LOCATION.findall(message):
+        file = find_file(location[0].replace(".", "/") + ".java")
+        if file:
+            return file, location[1]
+
+    return None
+
+
+def parse_junit() -> None:
+    """
+    Scrape JUnit test reports for errors. We determine the location from the Lua
+    or Java stacktrace.
+    """
+    print("::add-matcher::.github/matchers/junit.json")
+
+    for path in pathlib.Path("build/test-results/test").glob("TEST-*.xml"):
+        for testcase in ET.parse(path).getroot():
+            if testcase.tag != "testcase":
+                continue
+
+            for result in testcase:
+                if result.tag != "failure":
+                    continue
+
+                name = f'{testcase.attrib["classname"]}.{testcase.attrib["name"]}'
+                message = result.attrib.get('message')
+
+                location = find_location(result.text)
+                error = ERROR_MESSAGE.match(message)
+                if error:
+                    error = error[1]
+                else:
+                    error = message
+
+                if location:
+                    print(f'## {location[0]}:{location[1]}: {name} failed: {SPACES.sub(" ", error)}')
+                else:
+                    print(f'::error::{name} failed')
+
+                print("::group::Full error message")
+                print(result.text)
+                print("::endgroup")
+
+    print("::remove-matcher owner=junit::")
+
+
+def parse_checkstyle() -> None:
+    """
+    Scrape JUnit test reports for errors. We determine the location from the Lua
+    or Java stacktrace.
+    """
+    print("::add-matcher::.github/matchers/checkstyle.json")
+
+    for path in pathlib.Path("build/reports/checkstyle/").glob("*.xml"):
+        for file in ET.parse(path).getroot():
+            for error in file:
+                filename = os.path.relpath(file.attrib['name'])
+
+                attrib = error.attrib
+                print(f'{attrib["severity"]} {filename}:{attrib["line"]}:{attrib.get("column", 1)}: {SPACES.sub(" ", attrib["message"])}')
+
+    print("::remove-matcher owner=checkstyle::")
+
+if __name__ == '__main__':
+    parse_junit()
+    parse_checkstyle()