feat(flipt): Add Flipt provider in openfeature-js (#724)

Signed-off-by: Yoofi Quansah <ybquansah@gmail.com>
Signed-off-by: Mark Phelps <209477+markphelps@users.noreply.github.com>

.github/component_owners.yml

@@ -22,6 +22,8 @@ components:
     - kinyoklion
     - mateoc
     - sago2k8
+  libs/providers/flipt:
+    - yquansah
 
 ignored-authors:
   - renovate-bot

.release-please-manifest.json

@@ -7,5 +7,6 @@
   "libs/providers/config-cat": "0.4.0",
   "libs/providers/launchdarkly-client": "0.2.0",
   "libs/providers/go-feature-flag-web": "0.1.5",
-  "libs/shared/flagd-core": "0.1.8"
+  "libs/shared/flagd-core": "0.1.8",
+  "libs/providers/flipt": "0.0.1"
 }

libs/providers/flipt/.eslintrc.json

@@ -0,0 +1,25 @@
+{
+  "extends": ["../../../.eslintrc.json"],
+  "ignorePatterns": ["!**/*"],
+  "overrides": [
+    {
+      "files": ["*.ts", "*.tsx", "*.js", "*.jsx"],
+      "rules": {}
+    },
+    {
+      "files": ["*.ts", "*.tsx"],
+      "rules": {}
+    },
+    {
+      "files": ["*.js", "*.jsx"],
+      "rules": {}
+    },
+    {
+      "files": ["*.json"],
+      "parser": "jsonc-eslint-parser",
+      "rules": {
+        "@nx/dependency-checks": "error"
+      }
+    }
+  ]
+}

libs/providers/flipt/README.md

@@ -0,0 +1,76 @@
+# Flipt Provider
+
+[Flipt](https://www.flipt.io/) is an open source developer friendly feature flagging solution, that allows for easy management and fast feature evaluation.
+
+This provider is an implementation on top of the official [Flipt Node Server Side SDK](https://www.npmjs.com/package/@flipt-io/flipt).
+
+## Installation
+
+```
+$ npm install @openfeature/flipt-provider
+```
+
+### Peer Dependencies
+
+Both the OpenFeature SDK and the Flipt Node Server SDK are required as peer dependencies.
+
+Please make sure to install `@flipt/flipt-io` at versions >= `1.0.0`, as the client API is different in earlier versions.
+
+The peer dependency will also enforce the above version.
+
+## Example initialization and usage
+
+To initialize the OpenFeature client with Flipt, you can use the following code snippet:
+
+```ts
+import { FliptProvider } from '@openfeature/flipt';
+
+const provider = new FliptProvider('namespace-of-choice', { url: 'http://your.upstream.flipt.host' });
+OpenFeature.setProvider(provider);
+```
+
+After the provider gets initialized, you can start evaluations of feature flags like so:
+
+```ts
+const client = OpenFeature.getClient();
+const details = await client.getStringDetails('nonExistent', 'default', {
+  targetingKey: 'myentity',
+  email: 'john@flipt.io',
+});
+```
+
+## Evaluation Context Transformation
+
+OpenFeature standardizes the evaluation context to include a `targetingKey`, and some other additional arbitrary properties that each provider can use fit for their use case.
+
+For Flipt, we translate the `targetingKey` as the `entityId`, and the rest of the OpenFeature evaluation context as the `context` in Flipt vernacular. You can find the meaning of those two words [here](https://www.flipt.io/docs/reference/evaluation/variant-evaluation) in our API docs.
+
+For example, an OpenFeature Evaluation context that has this structure:
+
+```json
+{
+  "targetingKey": "my-targeting-id",
+  "email": "john@flipt.io",
+  "userId": "this-very-long-user-id"
+}
+```
+
+will get transformed to the following for Flipt:
+
+```json
+{
+  "entityId": "my-targeting-id",
+  "context": {
+    "email": "john@flipt.io",
+    "userId": "this-very-long-user-id"
+  }
+}
+```
+
+## Building
+
+Run `nx package providers-flipt` to build the library.
+
+## Running unit tests
+
+Run `nx test providers-flipt` to execute the unit tests via [Jest](https://jestjs.io).

libs/providers/flipt/babel.config.json

@@ -0,0 +1,3 @@
+{
+  "presets": [["minify", { "builtIns": false }]]
+}

libs/providers/flipt/jest.config.ts

@@ -0,0 +1,10 @@
+/* eslint-disable */
+export default {
+  displayName: 'providers-flipt',
+  preset: '../../../jest.preset.js',
+  transform: {
+    '^.+\\.[tj]s$': ['ts-jest', { tsconfig: '<rootDir>/tsconfig.spec.json' }],
+  },
+  moduleFileExtensions: ['ts', 'js', 'html'],
+  coverageDirectory: '../../../coverage/libs/providers/flipt',
+};

libs/providers/flipt/package.json

@@ -0,0 +1,17 @@
+{
+  "name": "@openfeature/flipt-provider",
+  "version": "0.0.1",
+  "dependencies": {
+    "tslib": "^2.3.0"
+  },
+  "main": "./src/index.js",
+  "typings": "./src/index.d.ts",
+  "scripts": {
+    "publish-if-not-exists": "cp $NPM_CONFIG_USERCONFIG .npmrc && if [ \"$(npm show $npm_package_name@$npm_package_version version)\" = \"$(npm run current-version -s)\" ]; then echo 'already published, skipping'; else npm publish --access public; fi",
+    "current-version": "echo $npm_package_version"
+  },
+  "peerDependencies": {
+    "@openfeature/server-sdk": "^1.6.0",
+    "@flipt-io/flipt": "^1.0.0"
+  }
+}

libs/providers/flipt/project.json

@@ -0,0 +1,76 @@
+{
+  "name": "providers-flipt",
+  "$schema": "../../../node_modules/nx/schemas/project-schema.json",
+  "sourceRoot": "libs/providers/flipt/src",
+  "projectType": "library",
+  "targets": {
+    "publish": {
+      "executor": "nx:run-commands",
+      "options": {
+        "command": "npm run publish-if-not-exists",
+        "cwd": "dist/libs/providers/flipt"
+      },
+      "dependsOn": [
+        {
+          "projects": "self",
+          "target": "package"
+        }
+      ]
+    },
+    "lint": {
+      "executor": "@nx/linter:eslint",
+      "outputs": ["{options.outputFile}"],
+      "options": {
+        "lintFilePatterns": ["libs/providers/flipt/**/*.ts", "libs/providers/flipt/package.json"]
+      }
+    },
+    "test": {
+      "executor": "@nx/jest:jest",
+      "outputs": ["{workspaceRoot}/coverage/{projectRoot}"],
+      "options": {
+        "jestConfig": "libs/providers/flipt/jest.config.ts",
+        "passWithNoTests": true
+      },
+      "configurations": {
+        "ci": {
+          "ci": true,
+          "codeCoverage": true
+        }
+      }
+    },
+    "package": {
+      "executor": "@nx/rollup:rollup",
+      "outputs": ["{options.outputPath}"],
+      "options": {
+        "project": "libs/providers/flipt/package.json",
+        "outputPath": "dist/libs/providers/flipt",
+        "entryFile": "libs/providers/flipt/src/index.ts",
+        "tsConfig": "libs/providers/flipt/tsconfig.lib.json",
+        "buildableProjectDepsInPackageJsonType": "dependencies",
+        "compiler": "tsc",
+        "generateExportsField": true,
+        "umdName": "flipt",
+        "external": "all",
+        "format": ["cjs", "esm"],
+        "assets": [
+          {
+            "glob": "package.json",
+            "input": "./assets",
+            "output": "./src/"
+          },
+          {
+            "glob": "LICENSE",
+            "input": "./",
+            "output": "./"
+          },
+          {
+            "glob": "README.md",
+            "input": "./libs/providers/flipt",
+            "output": "./"
+          }
+        ]
+      }
+    }
+  },
+  "tags": []
+}

libs/providers/flipt/src/index.ts

@@ -0,0 +1 @@
+export * from './lib/flipt-provider';

libs/providers/flipt/src/lib/context-transformer.spec.ts

@@ -0,0 +1,18 @@
+import { EvaluationContext } from '@openfeature/server-sdk';
+import { transformContext } from './context-transformer';
+
+describe('context-transformer', () => {
+  describe('transformContext', () => {
+    it('should transform context correctly', () => {
+      const context: EvaluationContext = {
+        targetingKey: 'entity',
+        customProp: 'test',
+      };
+
+      const transformedContext: Record<string, string> = transformContext(context);
+
+      expect(transformedContext['customProp']).toBe('test');
+      expect(transformedContext['targetingKey']).toBeUndefined();
+    });
+  });
+});

libs/providers/flipt/src/lib/context-transformer.ts

@@ -0,0 +1,12 @@
+import { EvaluationContext } from '@openfeature/server-sdk';
+
+export function transformContext(context: EvaluationContext): Record<string, string> {
+  const evalContext: Record<string, string> = {};
+  for (const value in context) {
+    if (value !== 'targetingKey') {
+      evalContext[value] = context[value]?.toString() ?? '';
+    }
+  }
+
+  return evalContext;
+}