fix capture to file

src/flake8_json_reporter/reporters.py

@@ -32,6 +32,7 @@ def start(self):
     def stop(self):
         """Override the default to finish printing JSON."""
         self.write_line("}")
+        super().stop()
 
     def beginning(self, filename):
         """We're starting a new file."""
@@ -83,6 +84,8 @@ def stop(self):
         if self.files_reported_count > 0:
             self.write_line("\n")
         self.write_line("}\n")
+        # DefaultJSON.stop would write and extra close brace
+        base.BaseFormatter.stop(self)
 
     def beginning(self, filename):
         """We're starting a new file."""
@@ -139,6 +142,7 @@ def start(self):
     def stop(self):
         """Override the default to finish printing JSON."""
         self.write_line("}")
+        super().stop()
 
     def beginning(self, filename):
         """We're starting a new file."""

tests/flake8_json_reporter_test.py

@@ -1,8 +1,10 @@
+import json
 from argparse import Namespace
 
 import pytest
 from flake8.violation import Violation
 
+from flake8_json_reporter.reporters import DefaultJSON
 from flake8_json_reporter.reporters import FormattedJSON
 
 
@@ -14,6 +16,26 @@ def formatter():
     return formatter
 
 
+@pytest.fixture
+def default_formatter_output_file(tmp_path):
+    """Return a ``DefaultJSON`` instance that captures output to a file"""
+    options = Namespace(
+        output_file=tmp_path / "output.json", color=False, tee=False
+    )
+    formatter = DefaultJSON(options)
+    return formatter
+
+
+@pytest.fixture
+def pretty_formatter_output_file(tmp_path):
+    """Return a ``DefaultJSON`` instance that captures output to a file"""
+    options = Namespace(
+        output_file=tmp_path / "output.json", color=False, tee=False
+    )
+    formatter = FormattedJSON(options)
+    return formatter
+
+
 @pytest.fixture
 def violation():
     return Violation(
@@ -119,3 +141,61 @@ def test_single_file_multiple_violations(capsys, formatter, violation):
 }
 """
     assert stdout == expected
+
+
+def test_pretty_single_file_single_file_capture(
+    pretty_formatter_output_file, violation
+):
+    run(pretty_formatter_output_file, {"main.py": [violation]})
+    expected = """\
+{
+  "main.py": [
+    {
+      "code": "E222",
+      "filename": "main.py",
+      "line_number": 42,
+      "column_number": 4,
+      "text": "multiple spaces after operator",
+      "physical_line": "x =  1"
+    }
+  ]
+}
+"""
+    actual = pretty_formatter_output_file.filename.read_text()
+    assert actual == expected
+
+
+def test_default_no_files_file_capture(default_formatter_output_file):
+    run(default_formatter_output_file, {})
+    expected = {}
+    actual = json.loads(default_formatter_output_file.filename.read_text())
+    assert actual == expected
+
+
+def test_default_single_file_no_violations_file_capture(
+    default_formatter_output_file,
+):
+    run(default_formatter_output_file, {"main.py": []})
+    expected = {"main.py": []}
+    actual = json.loads(default_formatter_output_file.filename.read_text())
+    assert actual == expected
+
+
+def test_default_single_file_violations_file_capture(
+    default_formatter_output_file, violation
+):
+    run(default_formatter_output_file, {"main.py": [violation]})
+    expected = {
+        "main.py": [
+            {
+                "code": "E222",
+                "filename": "main.py",
+                "line_number": 42,
+                "column_number": 4,
+                "text": "multiple spaces after operator",
+                "physical_line": "x =  1",
+            }
+        ]
+    }
+    actual = json.loads(default_formatter_output_file.filename.read_text())
+    assert actual == expected