force version non conflict diff when base version is missing

x-pack/plugins/security_solution/server/lib/detection_engine/prebuilt_rules/logic/diff/calculation/algorithms/force_target_version_diff_algorithm.test.ts

@@ -0,0 +1,78 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License
+ * 2.0; you may not use this file except in compliance with the Elastic License
+ * 2.0.
+ */
+
+import type { ThreeVersionsOf } from '../../../../../../../../common/api/detection_engine';
+import {
+  ThreeWayMergeOutcome,
+  MissingVersion,
+  ThreeWayDiffConflict,
+} from '../../../../../../../../common/api/detection_engine';
+import { forceTargetVersionDiffAlgorithm } from './force_target_version_diff_algorithm';
+
+describe('forceTargetVersionDiffAlgorithm', () => {
+  describe('when base version exists', () => {
+    it('returns a NON conflict diff', () => {
+      const mockVersions: ThreeVersionsOf<number> = {
+        base_version: 1,
+        current_version: 1,
+        target_version: 2,
+      };
+
+      const result = forceTargetVersionDiffAlgorithm(mockVersions);
+
+      expect(result).toMatchObject({
+        conflict: ThreeWayDiffConflict.NONE,
+      });
+    });
+
+    it('return merge outcome TARGET', () => {
+      const mockVersions: ThreeVersionsOf<number> = {
+        base_version: 1,
+        current_version: 1,
+        target_version: 2,
+      };
+
+      const result = forceTargetVersionDiffAlgorithm(mockVersions);
+
+      expect(result).toMatchObject({
+        has_base_version: true,
+        merge_outcome: ThreeWayMergeOutcome.Target,
+      });
+    });
+  });
+
+  describe('when base version missing', () => {
+    it('returns a NON conflict diff', () => {
+      const mockVersions: ThreeVersionsOf<number> = {
+        base_version: MissingVersion,
+        current_version: 1,
+        target_version: 2,
+      };
+
+      const result = forceTargetVersionDiffAlgorithm(mockVersions);
+
+      expect(result).toMatchObject({
+        conflict: ThreeWayDiffConflict.NONE,
+      });
+    });
+
+    it('return merge outcome TARGET', () => {
+      const mockVersions: ThreeVersionsOf<number> = {
+        base_version: MissingVersion,
+        current_version: 1,
+        target_version: 2,
+      };
+
+      const result = forceTargetVersionDiffAlgorithm(mockVersions);
+
+      expect(result).toMatchObject({
+        has_base_version: false,
+        merge_outcome: ThreeWayMergeOutcome.Target,
+      });
+    });
+  });
+});

x-pack/plugins/security_solution/server/lib/detection_engine/prebuilt_rules/logic/diff/calculation/algorithms/force_target_version_diff_algorithm.ts

@@ -0,0 +1,45 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License
+ * 2.0; you may not use this file except in compliance with the Elastic License
+ * 2.0.
+ */
+
+import type {
+  ThreeVersionsOf,
+  ThreeWayDiff,
+} from '../../../../../../../../common/api/detection_engine/prebuilt_rules';
+import {
+  MissingVersion,
+  ThreeWayDiffConflict,
+  ThreeWayMergeOutcome,
+  determineDiffOutcome,
+} from '../../../../../../../../common/api/detection_engine/prebuilt_rules';
+
+/**
+ * Diff algorithm forcing target version. Useful for special fields like `version`.
+ */
+export const forceTargetVersionDiffAlgorithm = <TValue>(
+  versions: ThreeVersionsOf<TValue>
+): ThreeWayDiff<TValue> => {
+  const {
+    base_version: baseVersion,
+    current_version: currentVersion,
+    target_version: targetVersion,
+  } = versions;
+  const hasBaseVersion = baseVersion !== MissingVersion;
+  const hasUpdate = targetVersion !== currentVersion;
+
+  return {
+    has_base_version: hasBaseVersion,
+    base_version: hasBaseVersion ? baseVersion : undefined,
+    current_version: currentVersion,
+    target_version: targetVersion,
+    merged_version: targetVersion,
+    merge_outcome: ThreeWayMergeOutcome.Target,
+
+    diff_outcome: determineDiffOutcome(baseVersion, currentVersion, targetVersion),
+    has_update: hasUpdate,
+    conflict: ThreeWayDiffConflict.NONE,
+  };
+};

x-pack/plugins/security_solution/server/lib/detection_engine/prebuilt_rules/logic/diff/calculation/algorithms/index.ts

@@ -15,3 +15,4 @@ export { kqlQueryDiffAlgorithm } from './kql_query_diff_algorithm';
 export { eqlQueryDiffAlgorithm } from './eql_query_diff_algorithm';
 export { esqlQueryDiffAlgorithm } from './esql_query_diff_algorithm';
 export { ruleTypeDiffAlgorithm } from './rule_type_diff_algorithm';
+export { forceTargetVersionDiffAlgorithm } from './force_target_version_diff_algorithm';

x-pack/plugins/security_solution/server/lib/detection_engine/prebuilt_rules/logic/diff/calculation/calculate_rule_fields_diff.ts

@@ -48,6 +48,7 @@ import {
   eqlQueryDiffAlgorithm,
   esqlQueryDiffAlgorithm,
   ruleTypeDiffAlgorithm,
+  forceTargetVersionDiffAlgorithm,
 } from './algorithms';
 
 const BASE_TYPE_ERROR = `Base version can't be of different rule type`;
@@ -179,7 +180,11 @@ const calculateCommonFieldsDiff = (
 
 const commonFieldsDiffAlgorithms: FieldsDiffAlgorithmsFor<DiffableCommonFields> = {
   rule_id: simpleDiffAlgorithm,
-  version: numberDiffAlgorithm,
+  /**
+   * `version` shouldn't have a conflict. It always get target value automatically.
+   * Diff has informational purpose.
+   */
+  version: forceTargetVersionDiffAlgorithm,
   name: singleLineStringDiffAlgorithm,
   tags: scalarArrayDiffAlgorithm,
   description: multiLineStringDiffAlgorithm,