feat: multi provider implementation for Node

.release-please-manifest.json

@@ -14,5 +14,6 @@
   "libs/providers/flipt": "0.1.0",
   "libs/providers/flagsmith-client": "0.1.2",
   "libs/providers/flipt-web": "0.1.0",
+  "libs/providers/multi-provider": "0.1.0",
   "libs/providers/growthbook-client": "0.1.1"
 }

libs/providers/multi-provider/.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/multi-provider/README.md

@@ -0,0 +1,15 @@
+# Multi Provider
+
+## Installation
+
+```
+$ npm install @openfeature/multi-provider
+```
+
+## Building
+
+Run `nx package providers-multi-provider` to build the library.
+
+## Running unit tests
+
+Run `nx test providers-multi-provider` to execute the unit tests via [Jest](https://jestjs.io).

libs/providers/multi-provider/babel.config.json

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

libs/providers/multi-provider/jest.config.ts

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

libs/providers/multi-provider/package.json

@@ -0,0 +1,16 @@
+{
+  "name": "@openfeature/vendor-migration-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"
+  }
+}

libs/providers/multi-provider/project.json

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

libs/providers/multi-provider/src/index.ts

@@ -0,0 +1,2 @@
+export * from './lib/multi-provider';
+export * from './lib/errors';

libs/providers/multi-provider/src/lib/errors.ts

@@ -0,0 +1,19 @@
+import { ErrorCode, GeneralError, OpenFeatureError } from '@openfeature/server-sdk';
+
+export class ErrorWithCode extends OpenFeatureError {
+  constructor(
+    public code: ErrorCode,
+    message: string,
+  ) {
+    super(message);
+  }
+}
+
+export class AggregateError extends GeneralError {
+  constructor(
+    message: string,
+    public originalErrors: { source: string; error: unknown }[],
+  ) {
+    super(message);
+  }
+}

libs/providers/multi-provider/src/lib/hook-executor.ts

@@ -0,0 +1,65 @@
+import { EvaluationDetails, FlagValue, Hook, HookContext, HookHints, Logger } from '@openfeature/server-sdk';
+
+/**
+ * Utility for executing a set of hooks of each type. Implementation is largely copied from the main OpenFeature SDK.
+ */
+export class HookExecutor {
+  constructor(private logger: Logger) {}
+
+  async beforeHooks(hooks: Hook[] | undefined, hookContext: HookContext, hints: HookHints) {
+    const newContext = { ...hookContext.context };
+    for (const hook of hooks ?? []) {
+      // freeze the hookContext
+      Object.freeze(hookContext);
+
+      Object.assign(newContext, {
+        ...(await hook?.before?.(hookContext, Object.freeze(hints))),
+      });
+    }
+
+    // after before hooks, freeze the EvaluationContext.
+    return Object.freeze(newContext);
+  }
+
+  async afterHooks(
+    hooks: Hook[] | undefined,
+    hookContext: HookContext,
+    evaluationDetails: EvaluationDetails<FlagValue>,
+    hints: HookHints,
+  ) {
+    // run "after" hooks sequentially
+    for (const hook of hooks ?? []) {
+      await hook?.after?.(hookContext, evaluationDetails, hints);
+    }
+  }
+
+  async errorHooks(hooks: Hook[] | undefined, hookContext: HookContext, err: unknown, hints: HookHints) {
+    // run "error" hooks sequentially
+    for (const hook of hooks ?? []) {
+      try {
+        await hook?.error?.(hookContext, err, hints);
+      } catch (err) {
+        this.logger.error(`Unhandled error during 'error' hook: ${err}`);
+        if (err instanceof Error) {
+          this.logger.error(err.stack);
+        }
+        this.logger.error((err as Error)?.stack);
+      }
+    }
+  }
+
+  async finallyHooks(hooks: Hook[] | undefined, hookContext: HookContext, hints: HookHints) {
+    // run "finally" hooks sequentially
+    for (const hook of hooks ?? []) {
+      try {
+        await hook?.finally?.(hookContext, hints);
+      } catch (err) {
+        this.logger.error(`Unhandled error during 'finally' hook: ${err}`);
+        if (err instanceof Error) {
+          this.logger.error(err.stack);
+        }
+        this.logger.error((err as Error)?.stack);
+      }
+    }
+  }
+}