Adding FAIL_FAST option (#785)

lukas-krecan · Jul 3, 2024 · 8480045 · 8480045
1 parent 3ed8176
commit 8480045
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Showing 5 changed files with 49 additions and 21 deletions.
diff --git a/.editorconfig b/.editorconfig
@@ -113,7 +113,7 @@ ij_java_for_statement_wrap = off
 ij_java_generate_final_locals = false
 ij_java_generate_final_parameters = false
 ij_java_if_brace_force = never
-ij_java_imports_layout = *,|,javax.**,java.**,|,$*
+ij_java_imports_layout = $*,|,*
 ij_java_indent_case_from_switch = true
 ij_java_insert_inner_class_imports = false
 ij_java_insert_override_annotation = true

diff --git a/json-unit-core/src/main/java/net/javacrumbs/jsonunit/core/Option.java b/json-unit-core/src/main/java/net/javacrumbs/jsonunit/core/Option.java
@@ -48,5 +48,10 @@ public enum Option {
      * Ignores values but fails if value types are different.
      * When using within {@link ConfigurationWhen#then(Option, Option...)}, path to the node with ignored value should be passed.
      */
-    IGNORING_VALUES
+    IGNORING_VALUES,
+
+    /**
+     * Stops comparison at the first difference. Can bring performance boots to use-cases that do not need the full list of all differences.
+     */
+    FAIL_FAST
 }
diff --git a/json-unit-core/src/main/java/net/javacrumbs/jsonunit/core/internal/ComparisonMatrix.java b/json-unit-core/src/main/java/net/javacrumbs/jsonunit/core/internal/ComparisonMatrix.java
@@ -18,14 +18,15 @@
 import static java.lang.Math.min;
 import static java.util.Collections.unmodifiableList;
 import static java.util.stream.Collectors.toList;
+import static net.javacrumbs.jsonunit.core.Configuration.dummyDifferenceListener;
+import static net.javacrumbs.jsonunit.core.Option.FAIL_FAST;
 import static net.javacrumbs.jsonunit.core.internal.Diff.DEFAULT_DIFFERENCE_STRING;
 import static net.javacrumbs.jsonunit.core.internal.JsonUnitLogger.NULL_LOGGER;
 
 import java.util.ArrayList;
 import java.util.BitSet;
 import java.util.List;
 import net.javacrumbs.jsonunit.core.Configuration;
-import net.javacrumbs.jsonunit.core.listener.DifferenceListener;
 
 /**
  * Stores comparison result when comparing two arrays.
@@ -98,15 +99,12 @@ private static boolean isSimilar(Path path, Configuration configuration, Node ex
                 expected,
                 actual,
                 Path.create("", path.toElement(i).getFullPath()),
-                configuration.withDifferenceListener(failFastDifferenceListener),
+                configuration.withDifferenceListener(dummyDifferenceListener()).withOptions(FAIL_FAST),
                 NULL_LOGGER,
                 NULL_LOGGER,
                 DEFAULT_DIFFERENCE_STRING);
-        try {
-            return diff.similar();
-        } catch (DifferenceFoundException e) {
-            return false;
-        }
+
+        return diff.similar();
     }
 
     ComparisonMatrix compare() {
@@ -249,15 +247,4 @@ List<Integer> getMissing() {
     List<Integer> getExtra() {
         return extra;
     }
-
-    private static final DifferenceListener failFastDifferenceListener = (difference, context) -> {
-        throw new DifferenceFoundException();
-    };
-
-    private static final class DifferenceFoundException extends RuntimeException {
-        @Override
-        public synchronized Throwable fillInStackTrace() {
-            return this;
-        }
-    }
 }
diff --git a/json-unit-core/src/main/java/net/javacrumbs/jsonunit/core/internal/Diff.java b/json-unit-core/src/main/java/net/javacrumbs/jsonunit/core/internal/Diff.java
@@ -16,6 +16,7 @@
 package net.javacrumbs.jsonunit.core.internal;
 
 import static java.util.Collections.emptySet;
+import static net.javacrumbs.jsonunit.core.Option.FAIL_FAST;
 import static net.javacrumbs.jsonunit.core.Option.IGNORING_ARRAY_ORDER;
 import static net.javacrumbs.jsonunit.core.Option.IGNORING_EXTRA_ARRAY_ITEMS;
 import static net.javacrumbs.jsonunit.core.Option.IGNORING_EXTRA_FIELDS;
@@ -152,7 +153,11 @@ private void compare() {
             if (part.isMissingNode()) {
                 structureDifferenceFound(context, "Missing node in path \"%s\".", startPath);
             } else {
-                compareNodes(context);
+                try {
+                    compareNodes(context);
+                } catch (FailedFastException e) {
+                    // ignore, the difference is already in the `differences` list.
+                }
             }
             compared = true;
 
@@ -634,15 +639,24 @@ private List<Node> asList(Iterator<Node> elements) {
 
     private void structureDifferenceFound(Context context, String message, Object... arguments) {
         differences.add(new JsonDifference(context, message, arguments));
+        possiblyFailFast(context);
     }
 
     private void valueDifferenceFound(Context context, String message, Object... arguments) {
         differences.add(new JsonDifference(context, message, arguments));
+        possiblyFailFast(context);
     }
 
     private void reportValueDifference(Context context, String message, Object... arguments) {
         reportDifference(DifferenceImpl.different(context));
         valueDifferenceFound(context, message, arguments);
+        possiblyFailFast(context);
+    }
+
+    private void possiblyFailFast(Context context) {
+        if (hasOption(context.actualPath(), FAIL_FAST)) {
+            throw new FailedFastException();
+        }
     }
 
     private Set<String> commonFields(Map<String, Node> expectedFields, Map<String, Node> actualFields) {
@@ -719,4 +733,14 @@ private static JsonUnitLogger createLogger(String name) {
             return NULL_LOGGER;
         }
     }
+
+    /**
+     * Exception throw on the first difference when FAIL_FAST option is on.
+     */
+    private static final class FailedFastException extends RuntimeException {
+        @Override
+        public synchronized Throwable fillInStackTrace() {
+            return this;
+        }
+    }
 }
diff --git a/tests/test-base/src/main/java/net/javacrumbs/jsonunit/test/base/AbstractAssertJTest.java b/tests/test-base/src/main/java/net/javacrumbs/jsonunit/test/base/AbstractAssertJTest.java
@@ -2281,6 +2281,18 @@ void shouldIgnoreMultiplePathsWrittenSeparately() {
                 .isEqualTo("{\"c\":3}");
     }
 
+    @Test
+    void shouldFailFast() {
+        assertThatThrownBy(() -> assertThatJson("{\"a\":{\"a1\": 1},\"b\":{\"b1\": 1}}")
+                        .withOptions(Option.FAIL_FAST)
+                        .isEqualTo("{\"a\":{\"a1\": 2},\"b\":{\"b1\": 2}}"))
+                .hasMessage(
+                        """
+                    JSON documents are different:
+                    Different value found in node "a.a1", expected: <2> but was: <1>.
+                    """);
+    }
+
     private static final String json =
             """
         {