Package org.dbunit.assertion.comparer.value

Class IsActualEqualToExpectedJsonValueComparer

java.lang.Object

org.dbunit.assertion.comparer.value.ValueComparerBase

org.dbunit.assertion.comparer.value.ValueComparerTemplateBase

org.dbunit.assertion.comparer.value.IsActualEqualToExpectedJsonValueComparer

All Implemented Interfaces:

ValueComparer

public class IsActualEqualToExpectedJsonValueComparer
extends ValueComparerTemplateBase

ValueComparer implementation that verifies the actual value is semantically equal to the expected value by parsing both as JSON and comparing the resulting document trees, instead of comparing their raw text.

Databases that store native JSON (for example MySQL JSON, PostgreSQL json/jsonb, or H2 JSON) commonly reformat the text on storage: insignificant whitespace is stripped and object keys may be reordered. A plain string or DataType.compare(Object, Object) comparison then fails even when the expected and actual documents are equivalent. This comparer instead treats JSON object member order as insignificant while still treating JSON array element order as significant, matching JSON's own equality semantics. Special case: if both values are null, they match.

Requires the optional jackson-databind dependency (the same one used by JsonDataSet) on the classpath. Deliberately not exposed as a constant on ValueComparers, because that class eagerly instantiates every constant it declares; doing so here would force the optional dependency onto every consumer of ValueComparers, not only those comparing JSON columns. Construct this comparer directly instead.

Since:

3.5.0

Author:

Jeff Jensen

Field Summary

Fields inherited from class org.dbunit.assertion.comparer.value.ValueComparerBase

BASE_FAIL_MSG

Constructor Summary

Constructors

Constructor	Description
IsActualEqualToExpectedJsonValueComparer()

Method Summary

Modifier and Type	Method	Description
protected String	getFailPhrase()	Returns the text snippet for substitution in ValueComparerBase.BASE_FAIL_MSG.
protected boolean	isExpected(ITable expectedTable, ITable actualTable, int rowNum, String columnName, DataType dataType, Object expectedValue, Object actualValue)	Determines whether the actual value compares as expected against the expected value.
protected boolean	isJsonEqual(int rowNum, String columnName, Object expectedValue, Object actualValue)	Returns whether the expected and actual values parse as structurally equal JSON documents.

Methods inherited from class org.dbunit.assertion.comparer.value.ValueComparerTemplateBase

doCompare, makeFailMessage

Methods inherited from class org.dbunit.assertion.comparer.value.ValueComparerBase

compare, toString

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Details

IsActualEqualToExpectedJsonValueComparer

public IsActualEqualToExpectedJsonValueComparer()

Method Details

isExpected

protected boolean isExpected(ITable expectedTable,
 ITable actualTable,
 int rowNum,
 String columnName,
 DataType dataType,
 Object expectedValue,
 Object actualValue)
                      throws DatabaseUnitException

Description copied from class: ValueComparerTemplateBase

Determines whether the actual value compares as expected against the expected value.

Specified by:

isExpected in class ValueComparerTemplateBase

Parameters:

expectedTable - Table containing all expected results.

actualTable - Table containing all actual results.

rowNum - The current row number comparing.

columnName - The name of the current column comparing.

dataType - The DataType for the current column comparing.

expectedValue - The current expected value for the column.

actualValue - The current actual value for the column.

Returns:

true if comparing actual to expected is as expected.

Throws:

DatabaseUnitException - if the comparison cannot be performed.

isJsonEqual

protected boolean isJsonEqual(int rowNum,
 String columnName,
 Object expectedValue,
 Object actualValue)
                       throws DatabaseUnitException

Returns whether the expected and actual values parse as structurally equal JSON documents.

Parameters:

rowNum - the current row number comparing, used only to identify a parse failure.

columnName - the name of the current column comparing, used only to identify a parse failure.

expectedValue - the expected value.

actualValue - the actual value.

Returns:

true if both values parse as JSON and their document trees are equal.

Throws:

DatabaseUnitException - if either value cannot be converted to a string or parsed as JSON.

getFailPhrase

protected String getFailPhrase()

Description copied from class: ValueComparerTemplateBase

Returns the text snippet for substitution in ValueComparerBase.BASE_FAIL_MSG.

Specified by:

getFailPhrase in class ValueComparerTemplateBase

Returns:

The text snippet for substitution in ValueComparerBase.BASE_FAIL_MSG.