Prototyping: Revise CI (#371)

Introduces a test runner with test cases. Also significantly overhauls the GHA configuration.

.github/workflows/prototyping.yml

@@ -34,6 +34,11 @@ jobs:
       with:
         path: ~/.cabal/store
         key: prototyping-${{ runner.os }}-${{ matrix.agda }}
+    - uses: actions/cache@v2
+      id: luau-ast-cache
+      with:
+        path: ./build
+        key: prototyping-${{ runner.os }}-${{ hashFiles('Ast/**', 'Analysis/**', 'CLI/Ast.cpp', 'CLI/FileUtils.*')}}
     - name: install cabal
       run: sudo apt-get install -y cabal-install
     - name: cabal update
@@ -43,26 +48,35 @@ jobs:
       working-directory: prototyping
       run: |
         cabal install Agda-${{ matrix.agda }}
-        cabal install --lib scientific --package-env .
-        cabal install --lib vector --package-env .
-        cabal install --lib aeson --package-env .
-    - name: check examples
+        cabal install --lib scientific vector aeson --package-env .
+    - name: check targets
       working-directory: prototyping
-      run: ~/.cabal/bin/agda Examples.agda
+      run: |
+        ~/.cabal/bin/agda Examples.agda
+        ~/.cabal/bin/agda Properties.agda
     - name: build executables
       working-directory: prototyping
       run: |
         ~/.cabal/bin/agda --compile PrettyPrinter.agda
         ~/.cabal/bin/agda --compile Interpreter.agda
     - name: cmake configure
-      run: cmake .
+      if: steps.luau-ast-cache.outputs.cache-hit != 'true'
+      run: |
+        mkdir -p build
+        cd build
+        cmake build ../
     - name: cmake build luau-ast
-      run: cmake --build . --target Luau.Ast.CLI
-    - name: run smoketest
+      if: steps.luau-ast-cache.outputs.cache-hit != 'true'
+      run: |
+        cmake --build ./build --target Luau.Ast.CLI
+    - name: run tests
       working-directory: prototyping
       run: |
-        ../luau-ast Examples/SmokeTest.lua | ./PrettyPrinter > Examples/SmokeTestOutput.lua
-        ../luau-ast Examples/SmokeTest.lua | ./Interpreter
-    - name: diff smoketest
-      working-directory: prototyping
-      run: diff Examples/SmokeTest.lua Examples/SmokeTestOutput.lua
+        mkdir test-failures
+        python tests -l ../build/luau-ast --write-diff-failures --diff-failure-location test-failures/
+    - uses: actions/upload-artifact@v2
+      if: failure()
+      with:
+        name: test failures
+        path: prototyping/test-failures
+        retention-days: 5

prototyping/.gitignore

@@ -2,5 +2,11 @@
 *.agdai
 Main
 MAlonzo
+Examples
 PrettyPrinter
+Interpreter
+Properties
+!Tests/Interpreter
+!Tests/PrettyPrinter
 .ghc.*
+test-failures/

prototyping/README.md

@@ -25,3 +25,21 @@ and run!
 ```
   luau-ast Examples/SmokeTest.lua | ./PrettyPrinter
 ```
+
+## Testing
+
+We have a series of snapshot tests in the `Tests/` directory. You interact with the tests using the `tests` Python script in the `prototyping` directory. To simply run the tests, run:
+
+```sh
+tests --luau-cli ../build/luau-ast --build
+```
+
+This will build the test targets and run them. Run `tests --help` for information about all the command-line options.
+
+### Adding a new test
+
+To add a new test, add it to `Tests/{SUITE_NAME}/{CASE_NAME}`. You'll need an `in.lua` file and an `out.txt` file. The `in.lua` file is the input Luau source code, while the `out.txt` file is the expected output after running `luau-ast in.lua | test_executable`.
+
+### Updating a test
+
+If you make a change to the prototype that results in an expected change in behavior, you might want to update the test cases automatically. To do this, run `tests` with the `--accept-new-output` (`-a` for short) flag. Rather than diffing the output, this will overwrite the `out.txt` files for each test case with the actual result. Commit the resulting changes with your PR.

prototyping/Tests/Interpreter/return_nil/in.lua

@@ -0,0 +1,5 @@
+local function foo(x)
+	return nil
+end
+
+return foo(nil)

prototyping/Tests/Interpreter/return_nil/out.txt

@@ -0,0 +1 @@
+nil

prototyping/Tests/PrettyPrinter/smoke_test/in.lua

@@ -1,12 +1,12 @@
 local function id(x)
-  return x
+	return x
 end
 local function comp(f)
-  return function(g)
-    return function(x)
-      return f(g(x))
-    end
-  end
+	return function(g)
+		return function(x)
+			return f(g(x))
+		end
+	end
 end
 local id2 = comp(id)(id)
 local nil2 = id2(nil)

prototyping/tests

@@ -0,0 +1,197 @@
+#!/bin/python
+
+import argparse
+import difflib
+import enum
+import os
+import os.path
+import subprocess
+import sys
+
+SUITES = ["interpreter", "prettyprinter"]
+IN_FILE_NAME = "in.lua"
+OUT_FILE_NAME = "out.txt"
+SUITE_EXE_NAMES = {
+    "interpreter": "Interpreter",
+    "prettyprinter": "PrettyPrinter",
+}
+
+SUITE_ENTRY_POINTS = {
+    "interpreter": "Interpreter.agda",
+    "prettyprinter": "PrettyPrinter.agda",
+}
+
+SUITE_ROOTS = {
+    "interpreter": "Tests/Interpreter",
+    "prettyprinter": "Tests/PrettyPrinter",
+}
+
+class TestResultStatus(enum.Enum):
+    CLI_ERROR = 0
+    EXE_ERROR = 1
+    DIFF_ERROR = 2
+    SUCCESS = 3
+    WROTE_NEW = 4
+
+class DiffFailure:
+    def __init__(self, expected, actual):
+        self.expected = expected
+        self.actual = actual
+    
+    def diff_text(self):
+        diff_generator = difflib.context_diff(self.expected.splitlines(), self.actual.splitlines(), fromfile="expected", tofile="actual", n=3)
+        return "".join(diff_generator)
+    
+    def diff_html(self):
+        differ = difflib.HtmlDiff(tabsize=4)
+        return differ.make_file(self.expected.splitlines(), self.actual.splitlines(), fromdesc="Expected", todesc="Actual", context=True, numlines=5)
+
+class TestCaseResult:
+    def __init__(self, suite, case, status, details):
+        self.suite = suite
+        self.case = case
+        self.status = status
+        self.details = details
+    
+    def did_pass(self):
+        return self.status == TestResultStatus.SUCCESS or self.status == TestResultStatus.WROTE_NEW
+    
+    def to_string(self):
+        prefix = f"[{self.suite}/{self.case}]: "
+        if self.status == TestResultStatus.CLI_ERROR:
+            return f"{prefix}CLI ERROR: {self.details}"
+        elif self.status == TestResultStatus.EXE_ERROR:
+            return f"{prefix}EXE ERROR: {self.details}"
+        elif self.status == TestResultStatus.DIFF_ERROR:
+            text_diff = self.details.diff_text()
+            return f"{prefix}FAILED:\n{text_diff}"
+        elif self.status == TestResultStatus.SUCCESS:
+            return f"{prefix}SUCCEEDED"
+        elif self.status == TestResultStatus.WROTE_NEW:
+            return f"{prefix}WROTE NEW RESULT"
+    
+    def write_artifact(self, artifact_root):
+        if self.status != TestResultStatus.DIFF_ERROR:
+            return
+
+        filename = f"{self.suite}-{self.case}.out.html"
+        path = os.path.join(artifact_root, filename)
+        html = self.details.diff_html()
+        with open(path, "w") as file:
+            file.write(html)
+
+parser = argparse.ArgumentParser(description="Runs prototype test cases")
+parser.add_argument("--luau-cli", "-l", dest="cli_location", required=True, help="The location of luau-cli")
+parser.add_argument("--root", "-r", dest="prototype_root", required=False, default=os.getcwd(), help="The root of the prototype")
+parser.add_argument("--build", "-b", dest="build", action="store_true", default=True, help="Whether to automatically build required test binaries")
+parser.add_argument("--suite", "-s", dest="suites", action="append", default=[], choices=SUITES, help="Which test suites to run")
+parser.add_argument("--case", "-c", dest="cases", action="append", default=[], help="Which test cases to run")
+parser.add_argument("--accept-new-output", "-a", dest="snapshot", action="store_true", default=False, help="Whether to write the new output to files, instead of diffing against it")
+parser.add_argument("--write-diff-failures", dest="write_diffs", action="store_true", default=False, help="Whether to write test failure diffs to files")
+parser.add_argument("--diff-failure-location", dest="diff_location", default=None, help="Where to write diff failure files to")
+
+def build_suite(root, suite):
+    entry_point = SUITE_ENTRY_POINTS.get(suite)
+    if entry_point is None:
+        return (False, "Invalid suite")
+    
+    result = subprocess.run(["~/.cabal/bin/agda", "--compile", entry_point], shell=True, cwd=root, stdout=subprocess.PIPE, stderr=subprocess.STDOUT)
+    if result.returncode == 0:
+        return (True, None)
+    else:
+        return (False, result.stdout)
+
+def run_test(in_path, out_path, cli_path, exe_path, snapshot):
+    cli_result = subprocess.run([cli_path, in_path], capture_output=True)
+    if cli_result.returncode != 0:
+        return (TestResultStatus.CLI_ERROR, f"CLI error: {cli_result.stderr}")
+    
+    exe_result = subprocess.run(exe_path, input=cli_result.stdout, capture_output=True)
+    if exe_result.returncode != 0:
+        return (TestResultStatus.EXE_ERROR, f"Executable error; stdout:{exe_result.stdout}\n\nstderr: {exe_result.stderr}")
+    actual_result = exe_result.stdout.decode("utf-8")
+
+    if snapshot:
+        with open(out_path, "w") as out_file:
+            out_file.write(actual_result)
+            return (TestResultStatus.WROTE_NEW, None)
+    else:
+        with open(out_path, "r") as out_file:
+            expected_result = out_file.read()
+
+            if expected_result != actual_result:
+                return (TestResultStatus.DIFF_ERROR, DiffFailure(expected_result, actual_result))
+    
+    return (TestResultStatus.SUCCESS, None)
+
+def should_run_case(case_name, filters):
+    if len(filters) == 0:
+        return True
+
+    return any([f in case_name for f in filters])
+
+def run_test_suite(args, suite, suite_root, suite_exe):
+    results = []
+
+    for entry in os.listdir(suite_root):
+        if not should_run_case(entry, args.cases):
+            continue
+
+        case_path = os.path.join(suite_root, entry)
+        if os.path.isdir(case_path):
+            in_path = os.path.join(case_path, IN_FILE_NAME)
+            out_path = os.path.join(case_path, OUT_FILE_NAME)
+
+            if not os.path.exists(in_path) or not os.path.exists(out_path):
+                continue
+            
+            status, details = run_test(in_path, out_path, args.cli_location, suite_exe, args.snapshot)
+            result = TestCaseResult(suite, entry, status, details)
+            results.append(result)
+
+    return results
+
+def main():
+    args = parser.parse_args()
+
+    suites = args.suites if len(args.suites) > 0 else SUITES
+    root = os.path.abspath(args.prototype_root)
+
+    if args.build:
+        for suite in suites:
+            success, reason = build_suite(root, suite)
+
+            if not success:
+                print(f"Error building executable for test suite {suite}:\n{reason}")
+                sys.exit(1)
+            else:
+                print(f"Built executable for test suite {suite} successfully.")
+    
+    failed = False
+    for suite in suites:
+        suite_root = os.path.join(root, SUITE_ROOTS.get(suite))
+        suite_exe = os.path.join(root, SUITE_EXE_NAMES.get(suite))
+        print(f"Running test suite {suite}...")
+        results = run_test_suite(args, suite, suite_root, suite_exe)
+
+        passed = 0
+        total = len(results)
+
+        for result in results:
+            if result.did_pass():
+                passed += 1
+            else:
+                failed = True
+
+        print(f"Suite {suite} [{passed} / {total} passed]:")
+        for result in results:
+            print(result.to_string())
+
+            if args.write_diffs:
+                result.write_artifact(args.diff_location)
+    
+    if failed:
+        sys.exit(1)
+
+if __name__ == "__main__":
+    main()