From 9c5f402a677e3a37c366ac94ef676a5805d852b9 Mon Sep 17 00:00:00 2001
From: Ryan Lamb <4955475+kinyoklion@users.noreply.github.com>
Date: Fri, 22 Sep 2023 09:25:44 -0700
Subject: [PATCH] feat: Add flag version to migration op event. (#281)

---
 .../__tests__/MigrationOpTracker.test.ts      | 78 +++++++++++++++++++
 .../shared/sdk-server/src/LDClientImpl.ts     |  2 +
 .../src/MigrationOpEventConversion.ts         |  4 +
 .../sdk-server/src/MigrationOpTracker.ts      |  2 +
 .../src/api/data/LDMigrationOpEvent.ts        |  1 +
 5 files changed, 87 insertions(+)

diff --git a/packages/shared/sdk-server/__tests__/MigrationOpTracker.test.ts b/packages/shared/sdk-server/__tests__/MigrationOpTracker.test.ts
index 4c045717e..8346aa2b5 100644
--- a/packages/shared/sdk-server/__tests__/MigrationOpTracker.test.ts
+++ b/packages/shared/sdk-server/__tests__/MigrationOpTracker.test.ts
@@ -58,6 +58,83 @@ it('generates an event if the minimal requirements are met.', () => {
   });
 });
 
+it('can include the variation in the event', () => {
+  const tracker = new MigrationOpTracker(
+    'flag',
+    { user: 'bob' },
+    LDMigrationStage.Off,
+    LDMigrationStage.Off,
+    {
+      kind: 'FALLTHROUGH',
+    },
+    undefined,
+    1,
+  );
+
+  tracker.op('write');
+  tracker.invoked('old');
+
+  expect(tracker.createEvent()).toMatchObject({
+    contextKeys: { user: 'bob' },
+    evaluation: {
+      default: 'off',
+      key: 'flag',
+      reason: { kind: 'FALLTHROUGH' },
+      value: 'off',
+      variation: 1,
+    },
+    kind: 'migration_op',
+    measurements: [
+      {
+        key: 'invoked',
+        values: {
+          old: true,
+        },
+      },
+    ],
+    operation: 'write',
+  });
+});
+
+it('can include the version in the event', () => {
+  const tracker = new MigrationOpTracker(
+    'flag',
+    { user: 'bob' },
+    LDMigrationStage.Off,
+    LDMigrationStage.Off,
+    {
+      kind: 'FALLTHROUGH',
+    },
+    undefined,
+    undefined,
+    2,
+  );
+
+  tracker.op('write');
+  tracker.invoked('old');
+
+  expect(tracker.createEvent()).toMatchObject({
+    contextKeys: { user: 'bob' },
+    evaluation: {
+      default: 'off',
+      key: 'flag',
+      reason: { kind: 'FALLTHROUGH' },
+      value: 'off',
+      version: 2,
+    },
+    kind: 'migration_op',
+    measurements: [
+      {
+        key: 'invoked',
+        values: {
+          old: true,
+        },
+      },
+    ],
+    operation: 'write',
+  });
+});
+
 it('includes errors if at least one is set', () => {
   const tracker = new MigrationOpTracker(
     'flag',
@@ -250,6 +327,7 @@ it('can handle exceptions thrown in the consistency check method', () => {
     undefined,
     undefined,
     undefined,
+    undefined,
     logger,
   );
   tracker.op('read');
diff --git a/packages/shared/sdk-server/src/LDClientImpl.ts b/packages/shared/sdk-server/src/LDClientImpl.ts
index 3b8590ad7..80c94f904 100644
--- a/packages/shared/sdk-server/src/LDClientImpl.ts
+++ b/packages/shared/sdk-server/src/LDClientImpl.ts
@@ -336,6 +336,7 @@ export default class LDClientImpl implements LDClient {
                 reason,
                 checkRatio,
                 undefined,
+                undefined,
                 samplingRatio,
               ),
             });
@@ -352,6 +353,7 @@ export default class LDClientImpl implements LDClient {
               checkRatio,
               // Can be null for compatibility reasons.
               detail.variationIndex === null ? undefined : detail.variationIndex,
+              flag?.version,
               samplingRatio,
             ),
           });
diff --git a/packages/shared/sdk-server/src/MigrationOpEventConversion.ts b/packages/shared/sdk-server/src/MigrationOpEventConversion.ts
index f18348c30..75b6a1530 100644
--- a/packages/shared/sdk-server/src/MigrationOpEventConversion.ts
+++ b/packages/shared/sdk-server/src/MigrationOpEventConversion.ts
@@ -196,6 +196,10 @@ function validateEvaluation(evaluation: LDMigrationEvaluation): LDMigrationEvalu
     validated.variation = evaluation.variation;
   }
 
+  if (evaluation.version !== undefined && TypeValidators.Number.is(evaluation.version)) {
+    validated.version = evaluation.version;
+  }
+
   return validated;
 }
 
diff --git a/packages/shared/sdk-server/src/MigrationOpTracker.ts b/packages/shared/sdk-server/src/MigrationOpTracker.ts
index eb30be50b..9001e42fd 100644
--- a/packages/shared/sdk-server/src/MigrationOpTracker.ts
+++ b/packages/shared/sdk-server/src/MigrationOpTracker.ts
@@ -43,6 +43,7 @@ export default class MigrationOpTracker implements LDMigrationTracker {
     private readonly reason: LDEvaluationReason,
     private readonly checkRatio?: number,
     private readonly variation?: number,
+    private readonly version?: number,
     private readonly samplingRatio?: number,
     private readonly logger?: LDLogger,
   ) {}
@@ -123,6 +124,7 @@ export default class MigrationOpTracker implements LDMigrationTracker {
         default: this.defaultStage,
         reason: this.reason,
         variation: this.variation,
+        version: this.version,
       },
       measurements,
       samplingRatio: this.samplingRatio ?? 1,
diff --git a/packages/shared/sdk-server/src/api/data/LDMigrationOpEvent.ts b/packages/shared/sdk-server/src/api/data/LDMigrationOpEvent.ts
index c3e69d702..544a7b34c 100644
--- a/packages/shared/sdk-server/src/api/data/LDMigrationOpEvent.ts
+++ b/packages/shared/sdk-server/src/api/data/LDMigrationOpEvent.ts
@@ -13,6 +13,7 @@ export interface LDMigrationEvaluation {
   value: LDMigrationStage;
   default: LDMigrationStage;
   variation?: number;
+  version?: number;
   reason: LDEvaluationReason;
 }