fix bugs with subscribers and named fact maps

jest.config.js

@@ -7,9 +7,9 @@ module.exports = {
   collectCoverageFrom: ['./src/*.js'],
   coverageThreshold: {
     global: {
-      branches: 75,
-      functions: 85,
-      lines: 85,
+      branches: 80,
+      functions: 90,
+      lines: 90,
     },
   },
 };

src/engine.js

@@ -16,7 +16,7 @@ export const createRulesEngine = (
 
   const on = (event, subscriber) => {
     const set = eventMap.get(event);
-    set ? eventMap.set(event, new Set([subscriber])) : set.add(subscriber);
+    set ? set.add(subscriber) : eventMap.set(event, new Set([subscriber]));
     return () => eventMap.get(event).delete(subscriber);
   };
 

src/fact.map.processor.js

@@ -2,16 +2,16 @@ import { createEvaluator } from './evaluator';
 
 export const createFactMapProcessor = (validator, opts, emit) => (rule) => {
   const evaluator = createEvaluator(validator, opts, emit, rule);
-  return async (factMap, id) => {
-    emit('debug', { type: 'STARTING_FACT_MAP', rule, mapId: id });
+  return async (factMap, mapId) => {
+    emit('debug', { type: 'STARTING_FACT_MAP', rule, mapId, factMap });
 
     // flags for if there was an error processing the fact map
     // and if all evaluations in the fact map passed
     let error = false;
     let passed = true;
 
     const results = (
-      await Promise.all(Object.entries(factMap).map(evaluator(id)))
+      await Promise.all(Object.entries(factMap).map(evaluator(mapId)))
     ).reduce((acc, { factName, ...rest }) => {
       if (error) return acc;
       error = error || !!rest.error;
@@ -20,11 +20,17 @@ export const createFactMapProcessor = (validator, opts, emit) => (rule) => {
       return acc;
     }, {});
 
-    emit('debug', { type: 'FINISHED_FACT_MAP', rule, mapId: id, results });
+    emit('debug', {
+      type: 'FINISHED_FACT_MAP',
+      rule,
+      mapId,
+      results,
+      passed,
+      error,
+    });
 
-    // return the results in the same form they were passed in
     return {
-      [id]: {
+      [mapId]: {
         ...results,
         __passed: passed,
         __error: error,

src/index.d.ts

@@ -77,6 +77,16 @@ type StartingFactMapEvent = {
   type: 'STARTING_FACT_MAP';
   rule: string;
   mapId: string | number;
+  factMap: FactMap;
+};
+
+type FinishedFactMapEvent = {
+  type: 'FINISHED_FACT_MAP';
+  rule: string;
+  mapId: string | number;
+  results: FactMapResult;
+  passed: boolean;
+  error: boolean;
 };
 
 type StartingFactEvent = {

src/rule.runner.js

@@ -27,34 +27,36 @@ export const createRuleRunner = (validator, opts, emit) => {
       const ruleResults = await Promise.all(
         Array.isArray(interpolated)
           ? interpolated.map(process)
-          : Object.entries(interpolated).map(([factMap, id]) =>
-              process(factMap, id),
-            ),
+          : Object.entries(interpolated).map(async ([k, v]) => process(v, k)),
       );
 
       // create the context and evaluate whether the rules have passed or errored in a single loop
-      const { passed, error, context } = ruleResults.reduce(
-        ({ passed, error, context }, result) => {
+      const { passed, error, resultsContext } = ruleResults.reduce(
+        ({ passed, error, resultsContext }, result) => {
           if (error) return { error };
           passed =
             passed && Object.values(result).every(({ __passed }) => __passed);
           error = Object.values(result).some(({ __error }) => __error);
-          return { passed, error, context: { ...context, ...result } };
+          return {
+            passed,
+            error,
+            resultsContext: { ...resultsContext, ...result },
+          };
         },
         {
           passed: true,
           error: false,
-          context: {},
+          resultsContext: {},
         },
       );
 
-      const nextContext = { ...opts.context, results: context };
+      const nextContext = { ...opts.context, results: resultsContext };
       const ret = (rest = {}) => ({
         [rule]: {
           __error: error,
           __passed: passed,
           ...rest,
-          results: ruleResults,
+          results: resultsContext,
         },
       });
 
@@ -93,7 +95,7 @@ export const createRuleRunner = (validator, opts, emit) => {
                 rule,
                 interpolated,
                 context: opts.context,
-                result: { actions: actionResults, results: ruleResults },
+                result: { actions: actionResults, results: resultsContext },
               });
               return actionResults;
             })

test/engine.test.ts

@@ -40,6 +40,31 @@ describe('rules engine', () => {
     expect(call).toHaveBeenCalledWith({ message: 'Who are you?' });
   });
 
+  it('should execute a rule using a named fact map', async () => {
+    const rules = {
+      salutation: {
+        when: {
+          myFacts: {
+            firstName: { is: { type: 'string', pattern: '^J' } },
+          },
+        },
+        then: {
+          actions: [{ type: 'log', params: { message: 'Hi friend!' } }],
+        },
+        otherwise: {
+          actions: [{ type: 'call', params: { message: 'Who are you?' } }],
+        },
+      },
+    };
+    engine.setRules(rules);
+    await engine.run({ firstName: 'John' });
+    expect(log).toHaveBeenCalledWith({ message: 'Hi friend!' });
+    log.mockClear();
+    await engine.run({ firstName: 'Bill' });
+    expect(log).not.toHaveBeenCalled();
+    expect(call).toHaveBeenCalledWith({ message: 'Who are you?' });
+  });
+
   it('should process nested rules', async () => {
     const rules = {
       salutation: {

test/events.test.ts

@@ -0,0 +1,160 @@
+import createRulesEngine, { RulesEngine } from '../src';
+import { createAjvValidator } from './validators';
+
+describe('events', () => {
+  let engine: RulesEngine;
+  let log: jest.Mock;
+  let call: jest.Mock;
+
+  beforeEach(() => {
+    log = jest.fn();
+    call = jest.fn();
+    engine = createRulesEngine(createAjvValidator(), {
+      actions: { log, call },
+    });
+  });
+
+  it('should unsubscribe', async () => {
+    const rules = {
+      salutation: {
+        when: {
+          myFacts: {
+            firstName: { is: { type: 'string', pattern: '^J' } },
+          },
+        },
+        then: {
+          actions: [{ type: 'log', params: { message: 'Hi friend!' } }],
+        },
+        otherwise: {
+          actions: [{ type: 'call', params: { message: 'Who are you?' } }],
+        },
+      },
+    };
+    engine.setRules(rules);
+    const subscriber = jest.fn();
+    const unsub = engine.on('debug', subscriber);
+    await engine.run({ firstName: 'John' });
+    expect(subscriber).toHaveBeenCalled();
+    unsub();
+    subscriber.mockClear();
+    await engine.run({ firstName: 'John' });
+    expect(subscriber).not.toHaveBeenCalled();
+  });
+
+  it('should subscribe to debug events', async () => {
+    const rules = {
+      salutation: {
+        when: {
+          myFacts: {
+            firstName: { is: { type: 'string', pattern: '^J' } },
+          },
+        },
+        then: {
+          actions: [{ type: 'log', params: { message: 'Hi friend!' } }],
+        },
+        otherwise: {
+          actions: [{ type: 'call', params: { message: 'Who are you?' } }],
+        },
+      },
+    };
+    engine.setRules(rules);
+    const subscriber = jest.fn();
+    const context = { firstName: 'John' };
+    engine.on('debug', subscriber);
+    await engine.run(context);
+
+    expect(subscriber).toHaveBeenNthCalledWith(
+      1,
+      expect.objectContaining({
+        type: 'STARTING_RULE',
+        rule: 'salutation',
+        interpolated: rules.salutation.when,
+        context,
+      }),
+    );
+
+    expect(subscriber).toHaveBeenNthCalledWith(
+      2,
+      expect.objectContaining({
+        type: 'STARTING_FACT_MAP',
+        rule: 'salutation',
+        mapId: 'myFacts',
+        factMap: rules.salutation.when.myFacts,
+      }),
+    );
+
+    expect(subscriber).toHaveBeenNthCalledWith(
+      3,
+      expect.objectContaining({
+        type: 'STARTING_FACT',
+        rule: 'salutation',
+        mapId: 'myFacts',
+        factName: 'firstName',
+      }),
+    );
+
+    expect(subscriber).toHaveBeenNthCalledWith(
+      4,
+      expect.objectContaining({
+        type: 'EXECUTED_FACT',
+        rule: 'salutation',
+        mapId: 'myFacts',
+        path: undefined,
+        factName: 'firstName',
+        value: context.firstName,
+        resolved: context.firstName,
+      }),
+    );
+
+    expect(subscriber).toHaveBeenNthCalledWith(
+      5,
+      expect.objectContaining({
+        type: 'EVALUATED_FACT',
+        rule: 'salutation',
+        mapId: 'myFacts',
+        path: undefined,
+        factName: 'firstName',
+        value: 'John',
+        resolved: 'John',
+        is: { type: 'string', pattern: '^J' },
+        result: { result: true },
+      }),
+    );
+
+    expect(subscriber).toHaveBeenNthCalledWith(
+      6,
+      expect.objectContaining({
+        type: 'FINISHED_FACT_MAP',
+        rule: 'salutation',
+        mapId: 'myFacts',
+        results: {
+          firstName: { result: true, value: 'John', resolved: 'John' },
+        },
+        passed: true,
+        error: false,
+      }),
+    );
+
+    expect(subscriber).toHaveBeenNthCalledWith(
+      7,
+      expect.objectContaining({
+        type: 'FINISHED_RULE',
+        rule: 'salutation',
+        interpolated: rules.salutation.when,
+        context,
+        result: {
+          actions: [{ type: 'log', params: { message: 'Hi friend!' } }],
+          results: {
+            myFacts: expect.objectContaining({
+              firstName: {
+                result: true,
+                value: 'John',
+                resolved: 'John',
+              },
+            }),
+          },
+        },
+      }),
+    );
+  });
+});

test/validators.ts

@@ -4,7 +4,6 @@ export const createAjvValidator = () => {
   const ajv = new Ajv2019();
   return async (object: any, schema: any) => {
     const validate = ajv.compile(schema);
-    const result = validate(object);
-    return { result, errors: validate.errors };
+    return { result: validate(object) };
   };
 };