feat: Add typed variation methods.

contract-tests/index.js

@@ -31,7 +31,8 @@ app.get('/', (req, res) => {
       'migrations',
       'event-sampling',
       'config-override-kind',
-      'metric-kind'
+      'metric-kind',
+      'strongly-typed',
     ],
   });
 });

contract-tests/sdkClientEntity.js

@@ -124,10 +124,30 @@ export async function newSdkClientEntity(options) {
       case 'evaluate': {
         const pe = params.evaluate;
         if (pe.detail) {
-          return await client.variationDetail(pe.flagKey, pe.context || pe.user, pe.defaultValue);
+          switch(pe.valueType) {
+            case "bool":
+              return await client.boolVariationDetail(pe.flagKey, pe.context || pe.user, pe.defaultValue);
+            case "int": // Intentional fallthrough.
+            case "double":
+              return await client.numberVariationDetail(pe.flagKey, pe.context || pe.user, pe.defaultValue);
+            case "string":
+              return await client.stringVariationDetail(pe.flagKey, pe.context || pe.user, pe.defaultValue);
+            default:
+              return await client.variationDetail(pe.flagKey, pe.context || pe.user, pe.defaultValue);
+          }
+
         } else {
-          const value = await client.variation(pe.flagKey, pe.context || pe.user, pe.defaultValue);
-          return { value };
+          switch(pe.valueType) {
+            case "bool":
+              return {value: await client.boolVariation(pe.flagKey, pe.context || pe.user, pe.defaultValue)};
+            case "int": // Intentional fallthrough.
+            case "double":
+              return {value: await client.numberVariation(pe.flagKey, pe.context || pe.user, pe.defaultValue)};
+            case "string":
+              return {value: await client.stringVariation(pe.flagKey, pe.context || pe.user, pe.defaultValue)};
+            default:
+              return {value: await client.variation(pe.flagKey, pe.context || pe.user, pe.defaultValue)};
+          }
         }
       }
 
@@ -160,7 +180,7 @@ export async function newSdkClientEntity(options) {
 
       case 'migrationVariation':
         const migrationVariation = params.migrationVariation;
-        const res = await client.variationMigration(
+        const res = await client.migrationVariation(
           migrationVariation.key,
           migrationVariation.context,
           migrationVariation.defaultStage,

packages/shared/common/src/api/data/LDEvaluationDetail.ts

@@ -27,3 +27,22 @@ export interface LDEvaluationDetail {
    */
   reason: LDEvaluationReason;
 }
+
+export interface LDEvaluationDetailTyped<TFlag> {
+  /**
+   * The result of the flag evaluation. This will be either one of the flag's variations or
+   * the default value that was passed to `LDClient.variationDetail`.
+   */
+  value: TFlag;
+
+  /**
+   * The index of the returned value within the flag's list of variations, e.g. 0 for the
+   * first variation-- or `null` if the default value was returned.
+   */
+  variationIndex?: number | null;
+
+  /**
+   * An object describing the main factor that influenced the flag evaluation value.
+   */
+  reason: LDEvaluationReason;
+}

packages/shared/sdk-server/__tests__/LDClient.evaluation.test.ts

@@ -160,6 +160,99 @@ describe('given an LDClient with test data', () => {
     const valueB = await client.variation('my-feature-flag-1', userContextObject, 'default');
     expect(valueB).toEqual(true);
   });
+
+  it('evaluates with jsonVariation', async () => {
+    td.update(td.flag('flagkey').booleanFlag().on(true));
+    const boolRes: boolean = (await client.jsonVariation('flagkey', defaultUser, false)) as boolean;
+    expect(boolRes).toBe(true);
+
+    td.update(td.flag('flagkey').valueForAll(62));
+    const numericRes: number = (await client.jsonVariation(
+      'flagkey',
+      defaultUser,
+      false,
+    )) as number;
+    expect(numericRes).toBe(62);
+
+    td.update(td.flag('flagkey').valueForAll('potato'));
+    const stringRes: string = (await client.jsonVariation('flagkey', defaultUser, false)) as string;
+    expect(stringRes).toBe('potato');
+  });
+
+  it('evaluates an existing boolean flag', async () => {
+    td.update(td.flag('flagkey').booleanFlag().on(true));
+    expect(await client.boolVariation('flagkey', defaultUser, false)).toEqual(true);
+  });
+
+  it('it uses the default value when a boolean variation is for a flag of the wrong type', async () => {
+    td.update(td.flag('flagkey').valueForAll('potato'));
+    expect(await client.boolVariation('flagkey', defaultUser, false)).toEqual(false);
+  });
+
+  it('evaluates an existing numeric flag', async () => {
+    td.update(td.flag('flagkey').booleanFlag().valueForAll(18));
+    expect(await client.numberVariation('flagkey', defaultUser, 36)).toEqual(18);
+  });
+
+  it('it uses the default value when a numeric variation is for a flag of the wrong type', async () => {
+    td.update(td.flag('flagkey').valueForAll('potato'));
+    expect(await client.numberVariation('flagkey', defaultUser, 36)).toEqual(36);
+  });
+
+  it('evaluates an existing string flag', async () => {
+    td.update(td.flag('flagkey').booleanFlag().valueForAll('potato'));
+    expect(await client.stringVariation('flagkey', defaultUser, 'default')).toEqual('potato');
+  });
+
+  it('it uses the default value when a string variation is for a flag of the wrong type', async () => {
+    td.update(td.flag('flagkey').valueForAll(8));
+    expect(await client.stringVariation('flagkey', defaultUser, 'default')).toEqual('default');
+  });
+
+  it('evaluates an existing boolean flag with detail', async () => {
+    td.update(td.flag('flagkey').booleanFlag().on(true));
+    const res = await client.boolVariationDetail('flagkey', defaultUser, false);
+    expect(res.value).toEqual(true);
+    expect(res.reason.kind).toBe('FALLTHROUGH');
+  });
+
+  it('it uses the default value when a boolean variation is for a flag of the wrong type with detail', async () => {
+    td.update(td.flag('flagkey').valueForAll('potato'));
+    const res = await client.boolVariationDetail('flagkey', defaultUser, false);
+    expect(res.value).toEqual(false);
+    expect(res.reason.kind).toEqual('ERROR');
+    expect(res.reason.errorKind).toEqual('WRONG_TYPE');
+  });
+
+  it('evaluates an existing numeric flag with detail', async () => {
+    td.update(td.flag('flagkey').booleanFlag().valueForAll(18));
+    const res = await client.numberVariationDetail('flagkey', defaultUser, 36);
+    expect(res.value).toEqual(18);
+    expect(res.reason.kind).toBe('FALLTHROUGH');
+  });
+
+  it('it uses the default value when a numeric variation is for a flag of the wrong type with detail', async () => {
+    td.update(td.flag('flagkey').valueForAll('potato'));
+    const res = await client.numberVariationDetail('flagkey', defaultUser, 36);
+    expect(res.value).toEqual(36);
+    expect(res.reason.kind).toEqual('ERROR');
+    expect(res.reason.errorKind).toEqual('WRONG_TYPE');
+  });
+
+  it('evaluates an existing string flag with detail', async () => {
+    td.update(td.flag('flagkey').booleanFlag().valueForAll('potato'));
+    const res = await client.stringVariationDetail('flagkey', defaultUser, 'default');
+    expect(res.value).toEqual('potato');
+    expect(res.reason.kind).toBe('FALLTHROUGH');
+  });
+
+  it('it uses the default value when a string variation is for a flag of the wrong type with detail', async () => {
+    td.update(td.flag('flagkey').valueForAll(8));
+    const res = await client.stringVariationDetail('flagkey', defaultUser, 'default');
+    expect(res.value).toEqual('default');
+    expect(res.reason.kind).toEqual('ERROR');
+    expect(res.reason.errorKind).toEqual('WRONG_TYPE');
+  });
 });
 
 describe('given an offline client', () => {

packages/shared/sdk-server/__tests__/LDClient.migrations.test.ts

@@ -57,7 +57,7 @@ describe('given an LDClient with test data', () => {
       const defaultValue = Object.values(LDMigrationStage).find((item) => item !== value);
       // Verify the pre-condition that the default value is not the value under test.
       expect(defaultValue).not.toEqual(value);
-      const res = await client.variationMigration(
+      const res = await client.migrationVariation(
         flagKey,
         { key: 'test-key' },
         defaultValue as LDMigrationStage,
@@ -74,15 +74,15 @@ describe('given an LDClient with test data', () => {
     LDMigrationStage.RampDown,
     LDMigrationStage.Complete,
   ])('returns the default value if the flag does not exist: default = %p', async (stage) => {
-    const res = await client.variationMigration('no-flag', { key: 'test-key' }, stage);
+    const res = await client.migrationVariation('no-flag', { key: 'test-key' }, stage);
 
     expect(res.value).toEqual(stage);
   });
 
   it('produces an error event for a migration flag with an incorrect value', async () => {
     const flagKey = 'bad-migration';
     td.update(td.flag(flagKey).valueForAll('potato'));
-    const res = await client.variationMigration(flagKey, { key: 'test-key' }, LDMigrationStage.Off);
+    const res = await client.migrationVariation(flagKey, { key: 'test-key' }, LDMigrationStage.Off);
     expect(res.value).toEqual(LDMigrationStage.Off);
     expect(errors.length).toEqual(1);
     expect(errors[0].message).toEqual(