feat: improve eval performance, restructure lib, support flag metadata

Signed-off-by: Michael Beemer <[email protected]>

.gitmodules

@@ -1,9 +1,9 @@
 [submodule "libs/providers/flagd/schemas"]
 	path = libs/providers/flagd/schemas
-	url = https://github.com/open-feature/schemas.git
+	url = https://github.com/open-feature/flagd-schemas.git
 [submodule "libs/providers/flagd-web/schemas"]
 	path = libs/providers/flagd-web/schemas
-	url = https://github.com/open-feature/schemas
+	url = https://github.com/open-feature/flagd-schemas.git
 [submodule "libs/providers/flagd/spec"]
   path = libs/providers/flagd/spec
   url = https://github.com/open-feature/spec.git

libs/shared/flagd-core/package.json

@@ -1,15 +1,16 @@
 {
   "name": "@openfeature/flagd-core",
   "version": "0.2.5",
+  "license": "Apache-2.0",
   "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/core": ">=0.0.16"
+    "@openfeature/core": ">=1.6.0"
   },
   "dependencies": {
     "ajv": "^8.12.0",
     "tslib": "^2.3.0"
   }
-}
+}

libs/shared/flagd-core/src/lib/feature-flag.spec.ts

@@ -1,5 +1,13 @@
+import type { Logger } from '@openfeature/core';
 import { FeatureFlag, Flag } from './feature-flag';
 
+const logger: Logger = {
+  error: jest.fn(),
+  warn: jest.fn(),
+  info: jest.fn(),
+  debug: jest.fn(),
+};
+
 describe('Flagd flag structure', () => {
   it('should be constructed with valid input - boolean', () => {
     const input: Flag = {
@@ -12,16 +20,35 @@ describe('Flagd flag structure', () => {
       targeting: '',
     };
 
-    const ff = new FeatureFlag(input);
+    const ff = new FeatureFlag('test', input, logger);
 
     expect(ff).toBeTruthy();
     expect(ff.state).toBe('ENABLED');
     expect(ff.defaultVariant).toBe('off');
-    expect(ff.targeting).toBe('');
     expect(ff.variants.get('on')).toBeTruthy();
     expect(ff.variants.get('off')).toBeFalsy();
   });
 
+  it('should be constructed with valid input - string', () => {
+    const input: Flag = {
+      state: 'ENABLED',
+      defaultVariant: 'off',
+      variants: {
+        on: 'on',
+        off: 'off',
+      },
+      targeting: '',
+    };
+
+    const ff = new FeatureFlag('test', input, logger);
+
+    expect(ff).toBeTruthy();
+    expect(ff.state).toBe('ENABLED');
+    expect(ff.defaultVariant).toBe('off');
+    expect(ff.variants.get('on')).toBe('on');
+    expect(ff.variants.get('off')).toBe('off');
+  });
+
   it('should be constructed with valid input - number', () => {
     const input: Flag = {
       state: 'ENABLED',
@@ -33,12 +60,11 @@ describe('Flagd flag structure', () => {
       targeting: '',
     };
 
-    const ff = new FeatureFlag(input);
+    const ff = new FeatureFlag('test', input, logger);
 
     expect(ff).toBeTruthy();
     expect(ff.state).toBe('ENABLED');
     expect(ff.defaultVariant).toBe('one');
-    expect(ff.targeting).toBe('');
     expect(ff.variants.get('one')).toBe(1.0);
     expect(ff.variants.get('two')).toBe(2.0);
   });
@@ -60,12 +86,11 @@ describe('Flagd flag structure', () => {
       targeting: '',
     };
 
-    const ff = new FeatureFlag(input);
+    const ff = new FeatureFlag('test', input, logger);
 
     expect(ff).toBeTruthy();
     expect(ff.state).toBe('ENABLED');
     expect(ff.defaultVariant).toBe('pi2');
-    expect(ff.targeting).toBe('');
     expect(ff.variants.get('pi2')).toStrictEqual({ value: 3.14, accuracy: 2 });
     expect(ff.variants.get('pi5')).toStrictEqual({ value: 3.14159, accuracy: 5 });
   });

libs/shared/flagd-core/src/lib/feature-flag.ts

@@ -1,5 +1,15 @@
-import { FlagValue, ParseError } from '@openfeature/core';
+import type {
+  FlagValue,
+  FlagMetadata,
+  ResolutionDetails,
+  JsonValue,
+  Logger,
+  EvaluationContext,
+  ResolutionReason,
+} from '@openfeature/core';
+import { ParseError, StandardResolutionReasons, ErrorCode } from '@openfeature/core';
 import { sha1 } from 'object-hash';
+import { Targeting } from './targeting/targeting';
 
 /**
  * Flagd flag configuration structure mapping to schema definition.
@@ -9,27 +19,66 @@ export interface Flag {
   defaultVariant: string;
   variants: { [key: string]: FlagValue };
   targeting?: string;
+  metadata?: FlagMetadata;
 }
 
+type RequiredResolutionDetails<T> = Omit<ResolutionDetails<T>, 'value'> & {
+  flagMetadata: FlagMetadata;
+} & (
+    | {
+        reason: 'ERROR';
+        errorCode: ErrorCode;
+        errorMessage: string;
+        value?: never;
+      }
+    | {
+        value: T;
+        variant: string;
+      }
+  );
+
 /**
  * Flagd flag configuration structure for internal reference.
  */
 export class FeatureFlag {
+  private readonly _key: string;
   private readonly _state: 'ENABLED' | 'DISABLED';
   private readonly _defaultVariant: string;
   private readonly _variants: Map<string, FlagValue>;
-  private readonly _targeting: unknown;
   private readonly _hash: string;
+  private readonly _metadata: FlagMetadata;
+  private readonly _targeting?: Targeting;
+  private readonly _targetingParseErrorMessage?: string;
 
-  constructor(flag: Flag) {
+  constructor(
+    key: string,
+    flag: Flag,
+    private readonly logger: Logger,
+  ) {
+    this._key = key;
     this._state = flag['state'];
     this._defaultVariant = flag['defaultVariant'];
     this._variants = new Map<string, FlagValue>(Object.entries(flag['variants']));
-    this._targeting = flag['targeting'];
+    this._metadata = flag['metadata'] ?? {};
+
+    if (flag.targeting && Object.keys(flag.targeting).length > 0) {
+      try {
+        this._targeting = new Targeting(flag.targeting, logger);
+      } catch (err) {
+        const message = `Invalid targeting configuration for flag '${key}'`;
+        this.logger.warn(message);
+        this._targetingParseErrorMessage = message;
+      }
+    }
     this._hash = sha1(flag);
+
     this.validateStructure();
   }
 
+  get key(): string {
+    return this._key;
+  }
+
   get hash(): string {
     return this._hash;
   }
@@ -42,14 +91,82 @@ export class FeatureFlag {
     return this._defaultVariant;
   }
 
-  get targeting(): unknown {
-    return this._targeting;
-  }
-
   get variants(): Map<string, FlagValue> {
     return this._variants;
   }
 
+  get metadata(): FlagMetadata {
+    return this._metadata;
+  }
+
+  evaluate(evalCtx: EvaluationContext, logger: Logger = this.logger): RequiredResolutionDetails<JsonValue> {
+    let variant: string;
+    let reason: ResolutionReason;
+
+    if (this._targetingParseErrorMessage) {
+      return {
+        reason: StandardResolutionReasons.ERROR,
+        errorCode: ErrorCode.PARSE_ERROR,
+        errorMessage: this._targetingParseErrorMessage,
+        flagMetadata: this.metadata,
+      };
+    }
+
+    if (!this._targeting) {
+      variant = this._defaultVariant;
+      reason = StandardResolutionReasons.STATIC;
+    } else {
+      let targetingResolution: JsonValue;
+      try {
+        targetingResolution = this._targeting.evaluate(this._key, evalCtx, logger);
+      } catch (e) {
+        logger.debug(`Error evaluating targeting rule for flag '${this._key}': ${(e as Error).message}`);
+        return {
+          reason: StandardResolutionReasons.ERROR,
+          errorCode: ErrorCode.GENERAL,
+          errorMessage: `Error evaluating targeting rule for flag '${this._key}'`,
+          flagMetadata: this.metadata,
+        };
+      }
+
+      // Return default variant if targeting resolution is null or undefined
+      if (targetingResolution === null || targetingResolution === undefined) {
+        variant = this._defaultVariant;
+        reason = StandardResolutionReasons.DEFAULT;
+      } else {
+        // Obtain resolution in string. This is useful for short-circuiting json logic
+        variant = targetingResolution.toString();
+        reason = StandardResolutionReasons.TARGETING_MATCH;
+      }
+    }
+
+    // if (typeof variant !== 'string') {
+    //   return {
+    //     reason: StandardResolutionReasons.ERROR,
+    //     errorCode: ErrorCode.GENERAL,
+    //     errorMessage: `Variant must be a string, but found '${typeof variant}'`,
+    //     flagMetadata: this.metadata,
+    //   };
+    // }
+
+    const resolvedVariant = this._variants.get(variant);
+    if (resolvedVariant === undefined) {
+      return {
+        reason: StandardResolutionReasons.ERROR,
+        errorCode: ErrorCode.GENERAL,
+        errorMessage: `Variant '${variant}' not found in flag with key '${this._key}'`,
+        flagMetadata: this.metadata,
+      };
+    }
+
+    return {
+      value: resolvedVariant,
+      reason,
+      variant,
+      flagMetadata: this.metadata,
+    };
+  }
+
   validateStructure() {
     // basic validation, ideally this sort of thing is caught by IDEs and other schema validation before we get here
     // consistent with Java/Go and other implementations, we only warn for schema validation, but we fail for this sort of basic structural errors