S19: establish engineering repository

tests/format_integration.py

@@ -0,0 +1,51 @@
+"""Integration checks against an isolated checkout; run python3 tooling/format/test.py."""
+from pathlib import Path
+import shutil
+import subprocess
+import tempfile
+
+root = Path(__file__).resolve().parents[1]
+with tempfile.TemporaryDirectory(prefix="palantir-test-") as temporary:
+    fixture = Path(temporary)
+    pom = (root / "templates/common/pom.xml").read_text().replace("@PROJECT@", "format-fixture").replace("@MODULES@", "")
+    (fixture / "pom.xml").write_text(pom)
+    (fixture / "generated/tooling").mkdir(parents=True)
+    shutil.copytree(root / "resources/tooling/format", fixture / "generated/tooling/format")
+    (fixture / "engineering.properties").write_text("FORMAT_DIRECTORIES=backend/src,ci\n")
+    for name in ("backend/src/main/java", "backend/src/test/java", "ci/runner"):
+        (fixture / name).mkdir(parents=True)
+    source = fixture / "ci/runner/Example.java"
+    original = "import java.util.List;\nclass Example{String text=\"héllo\";int value(){return 1;}}\n"
+    source.write_text(original)
+
+    def run(mode, success=True):
+        result = subprocess.run(
+            ["mvn", "-N", "-B", "-ntp", "exec:exec@format", "-Dformat.mode=" + mode],
+            cwd=fixture, text=True, stdout=subprocess.PIPE, stderr=subprocess.STDOUT)
+        assert (result.returncode == 0) == success, result.stdout
+        return result.stdout
+
+    output = run("check", False)
+    assert "ci/runner/Example.java" in output and "mvn -N exec:exec@format" in output
+    assert source.read_text() == original
+    run("apply")
+    formatted = source.read_text()
+    assert "import java.util.List" not in formatted and "héllo" in formatted
+    run("check")
+    run("apply")
+    assert source.read_text() == formatted
+    # Force a full (uncached) second pass to prove engine idempotence.
+    (fixture / "target/palantir-cache.properties").unlink()
+    run("check")
+    source.write_text(formatted + "class Broken { ??? }\n")
+    invalid = source.read_bytes()
+    output = run("apply", False)
+    assert "ci/runner/Example.java" in output
+    assert source.read_bytes() == invalid
+    # A new file is discovered even after a successful cached check.
+    source.write_text(formatted)
+    extra = fixture / "ci/New.java"
+    extra.write_text("class New{}")
+    run("check", False)
+    assert extra.read_text() == "class New{}"
+    print("PASS: check is read-only, apply/check agree, imports, UTF-8, idempotence, parser errors, new files")