test_indent.py

Overview

The [test_indent.py](/projects/287/67683) file is a test module designed to verify the behavior of the `orjson` JSON serialization library when used with indentation options. Specifically, it focuses on testing the `OPT_INDENT_2` option, which produces pretty-printed JSON output with an indentation level of 2 spaces. The tests ensure that `orjson`’s indented output is functionally equivalent to Python’s built-in `json.dumps` with `indent=2`, and also verify interactions with other serialization options like sorting keys, converting non-string dictionary keys to strings, and handling datetime objects.

This suite is part of a broader testing framework that uses fixtures loaded from compressed JSON files to validate `orjson`’s formatting against known reference data.

Classes and Methods

Class: TestIndentedOutput

A test class decorated with `@needs_data`, indicating that it requires preloaded test data fixtures for some tests (via the `read_fixture_obj` utility). This class contains multiple test methods that use Python's built-in `assert` statements to validate the correctness of `orjson`’s indented JSON serialization.

Methods

test_equivalent(self)

**Purpose:** Verifies that using `orjson.OPT_INDENT_2` produces JSON output equivalent to Python’s `json.dumps` with `indent=2`.

**Parameters:**

• self: The instance of the test class.

**Returns:**

• None. Raises an AssertionError if the output differs.

**Implementation Detail:**

• Serializes a nested dictionary with orjson.dumps using OPT_INDENT_2.

• Serializes the same dictionary with json.dumps using indent=2.

• Compares the byte output of orjson with the UTF-8 encoded string output of json.dumps.

**Usage Example:**

test = TestIndentedOutput()
test.test_equivalent()

test_sort(self)

**Purpose:** Checks that `orjson` correctly sorts dictionary keys when combined with indentation.

**Parameters:**

• self

**Returns:**

• None.

**Details:**

• Uses orjson.OPT_INDENT_2 | orjson.OPT_SORT_KEYS options.

• Serializes a dictionary with keys out of order and asserts that output is sorted and indented.

test_non_str(self)

**Purpose:** Tests the ability of `orjson` to convert non-string dictionary keys (e.g., integers) to strings in the output when using `OPT_NON_STR_KEYS` in combination with indentation.

**Parameters:**

• self

**Returns:**

• None.

**Details:**

• Serializes a dictionary with an integer key using OPT_INDENT_2 | OPT_NON_STR_KEYS.

• Ensures the integer key 1 appears as the string "1" in the output.

test_options(self)

**Purpose:** Validates combined usage of multiple options including indentation, key sorting, non-string keys, and naive UTC datetime formatting.

**Parameters:**

• self

**Returns:**

• None.

**Details:**

• Serializes a dictionary with integer keys, booleans, and a naive datetime object.

• Options used:
  OPT_INDENT_2 | OPT_SORT_KEYS | OPT_NON_STR_KEYS | OPT_NAIVE_UTC

• Confirms that datetime is formatted as an ISO8601 string with UTC offset.

test_empty(self)

**Purpose:** Ensures that empty structures (empty dicts, nested empty lists) are serialized with correct indentation.

**Parameters:**

• self

**Returns:**

• None.

**Details:**

• Serializes a complex nested list/dict structure containing empty collections.

• Compares result against a hardcoded indented byte string.

test_twitter_pretty(self)

**Purpose:** Tests pretty-printed output of a real-world large JSON fixture (`twitter.json`).

**Parameters:**

• self

**Returns:**

• None.

**Details:**

• Loads JSON data from a compressed fixture file twitter.json.xz.

• Asserts that orjson.dumps with OPT_INDENT_2 matches json.dumps with indent=2 and ensure_ascii=False.

test_github_pretty(self)

**Purpose:** Similar to `test_twitter_pretty` but using the `github.json` fixture.

**Parameters:**

• self

**Returns:**

• None.

test_canada_pretty(self)

**Purpose:** Tests pretty printing on `canada.json` fixture.

test_citm_catalog_pretty(self)

**Purpose:** Tests pretty printing on `citm_catalog.json` fixture.

Implementation Details and Algorithms

• The tests leverage bitwise OR to combine multiple orjson option flags.

• orjson.dumps returns a UTF-8 encoded bytes object, while json.dumps returns a string; comparisons encode json.dumps output to bytes for equality checks.

• The datetime serialization test uses the OPT_NAIVE_UTC option to serialize naive datetime objects as UTC ISO8601 strings.

• The test class is decorated with @needs_data to indicate reliance on external fixture data loaded via read_fixture_obj, suggesting a custom test setup that injects or prepares data for tests.

Interaction with Other Parts of the System

• Utilities: Imports needs_data and read_fixture_obj from .util.

  • needs_data is likely a decorator that prepares test data or fixtures before test execution.

  • read_fixture_obj loads and decompresses JSON fixture files (e.g., twitter.json.xz), providing consistent test inputs.

• orjson Library: The main subject under test, providing high-performance JSON serialization with optional formatting features.

• Python’s json Module: Used as a baseline for expected output, especially for pretty-printing with indentation.

This file functions primarily as a validation layer ensuring that `orjson`'s indentation and formatting options produce output consistent with the standard library's behavior or expected formatting, including complex real-world JSON datasets.

Usage Example

from test_indent import TestIndentedOutput

test = TestIndentedOutput()

# Run equivalence test
test.test_equivalent()

# Run sort keys and indent test
test.test_sort()

# Run combined options test
test.test_options()

Visual Diagram

classDiagram
    class TestIndentedOutput {
        +test_equivalent()
        +test_sort()
        +test_non_str()
        +test_options()
        +test_empty()
        +test_twitter_pretty()
        +test_github_pretty()
        +test_canada_pretty()
        +test_citm_catalog_pretty()
    }

    TestIndentedOutput ..> needs_data : decorator
    TestIndentedOutput ..> read_fixture_obj : uses in fixture tests
    TestIndentedOutput ..> orjson : tests serialization
    TestIndentedOutput ..> json : compares output

Summary

[test_indent.py](/projects/287/67683) is a focused test suite validating the `orjson` library’s pretty-printing capabilities. It ensures that indentation with two spaces matches Python’s standard library JSON formatting and verifies the correct combination of sorting keys, handling non-string keys, and datetime serialization. It also validates indented output on large, realistic JSON fixtures to detect regressions or formatting inconsistencies. This file is integral in maintaining the correctness and usability of `orjson`’s indentation features within the broader project.