initial commit

src/archipelago_tester/pipeline/generation/report.py

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+"""Reading what a driver reported."""
+
+import json
+
+
+class DriverReport:
+    """The JSON one driver run wrote to stdout."""
+
+    def __init__(self, result):
+        self.result = result
+
+    @staticmethod
+    def tail(text, lines=20):
+        return "\n".join(text.splitlines()[-lines:])
+
+    @staticmethod
+    def last_json_object(text):
+        """The driver's report, however it ended up on the line.
+
+        Not "the last line starting with {": worlds write to raw stdout
+        during generation, and one that writes without a trailing
+        newline leaves its output glued to the front of the report -
+        Super Metroid's randomizer emits a bare "*" per retry, so the
+        report arrives as "*{...}" and would read as no report at all.
+        """
+        for line in reversed(text.splitlines()):
+            line = line.strip()
+            start = line.find("{")
+            while start != -1:
+                try:
+                    return json.loads(line[start:])
+                except json.JSONDecodeError:
+                    start = line.find("{", start + 1)
+        return None
+
+    @property
+    def data(self):
+        return self.last_json_object(self.result.stdout)
+
+    def parsed(self):
+        """The report, or a failure built from what it printed."""
+        report = self.data
+        if report is not None:
+            report.setdefault("stderr_tail", self.tail(self.result.stderr))
+            return report
+        return {
+            "game": None,
+            "outcome": "failed",
+            "detail": ("no JSON report on stdout "
+                       f"(exit code {self.result.returncode})"),
+            "elapsed_seconds": None,
+            "stdout_tail": self.tail(self.result.stdout),
+            "stderr_tail": self.tail(self.result.stderr),
+        }