introduce formal rule visitor

src/app.ts

@@ -4,7 +4,8 @@ import { showCompletionScript } from 'yargs';
 import { loadConfig } from './config';
 import { CONFIG_ARGS_NAME, CONFIG_ARGS_PATH, MODE, parseArgs } from './config/args';
 import { YamlParser } from './parser/YamlParser';
-import { createRuleSelector, createRuleSources, loadRules, resolveRules, visitRules } from './rule';
+import { createRuleSelector, createRuleSources, loadRules, resolveRules } from './rule';
+import { RuleVisitor } from './rule/RuleVisitor';
 import { readSource, writeSource } from './source';
 import { VERSION_INFO } from './version';
 import { VisitorContext } from './visitor/VisitorContext';
@@ -59,8 +60,12 @@ export async function main(argv: Array<string>): Promise<number> {
   const source = await readSource(args.source);
   const docs = parser.parse(source);
 
-  for (const data of docs) {
-    await visitRules(ctx, activeRules, data);
+  const visitor = new RuleVisitor({
+    rules: activeRules,
+  });
+
+  for (const root of docs) {
+    await visitor.visit(ctx, root);
   }
 
   if (ctx.errors.length === 0) {

src/rule/RuleVisitor.ts

@@ -0,0 +1,65 @@
+import { applyDiff, diff } from 'deep-diff';
+import { cloneDeep } from 'lodash';
+
+import { Rule } from '.';
+import { hasItems } from '../utils';
+import { Visitor } from '../visitor';
+import { VisitorContext } from '../visitor/VisitorContext';
+
+/* eslint-disable @typescript-eslint/no-explicit-any */
+
+export interface RuleVisitorOptions {
+  rules: ReadonlyArray<Rule>;
+}
+
+export class RuleVisitor implements RuleVisitorOptions, Visitor {
+  public readonly rules: ReadonlyArray<Rule>;
+
+  constructor(options: RuleVisitorOptions) {
+    this.rules = Array.from(options.rules);
+  }
+
+  public async pick(ctx: VisitorContext, root: any): Promise<Array<any>> {
+    return []; // why is this part of visitor rather than rule?
+  }
+
+  public async visit(ctx: VisitorContext, root: any): Promise<VisitorContext> {
+    for (const rule of this.rules) {
+      const items = await rule.pick(ctx, root);
+      let itemIndex = 0;
+      for (const item of items) {
+        ctx.visitData = {
+          itemIndex,
+          rule,
+        };
+        const itemResult = cloneDeep(item);
+        const ruleResult = await rule.visit(ctx, itemResult);
+
+        if (hasItems(ruleResult.errors)) {
+          ctx.logger.warn({ count: ruleResult.errors.length, rule }, 'rule failed');
+          ctx.mergeResult(ruleResult, ctx.visitData);
+          continue;
+        }
+
+        const itemDiff = diff(item, itemResult);
+        if (hasItems(itemDiff)) {
+          ctx.logger.info({
+            diff: itemDiff,
+            item,
+            rule: rule.name,
+          }, 'rule passed with modifications');
+
+          if (ctx.schemaOptions.mutate) {
+            applyDiff(item, itemResult);
+          }
+        } else {
+          ctx.logger.info({ rule: rule.name }, 'rule passed');
+        }
+
+        itemIndex += 1;
+      }
+    }
+
+    return ctx;
+  }
+}

src/rule/index.ts

@@ -1,13 +1,12 @@
 import { ValidateFunction } from 'ajv';
-import { applyDiff, diff } from 'deep-diff';
-import { cloneDeep, Dictionary, intersection, isNil } from 'lodash';
+import { Dictionary, intersection, isNil } from 'lodash';
 import { Minimatch } from 'minimatch';
 import { LogLevel } from 'noicejs';
 import recursive from 'recursive-readdir';
 
 import { YamlParser } from '../parser/YamlParser';
 import { readFile } from '../source';
-import { ensureArray, hasItems } from '../utils';
+import { ensureArray } from '../utils';
 import { VisitorResult } from '../visitor';
 import { VisitorContext } from '../visitor/VisitorContext';
 import { SchemaRule } from './SchemaRule';
@@ -204,43 +203,3 @@ export async function resolveRules(rules: Array<Rule>, selector: RuleSelector):
 
   return Array.from(activeRules);
 }
-
-export async function visitRules(ctx: VisitorContext, rules: Array<Rule>, data: any): Promise<VisitorContext> {
-  for (const rule of rules) {
-    const items = await rule.pick(ctx, data);
-    let itemIndex = 0;
-    for (const item of items) {
-      ctx.visitData = {
-        itemIndex,
-        rule,
-      };
-      const itemResult = cloneDeep(item);
-      const ruleResult = await rule.visit(ctx, itemResult);
-
-      if (hasItems(ruleResult.errors)) {
-        ctx.logger.warn({ count: ruleResult.errors.length, rule }, 'rule failed');
-        ctx.mergeResult(ruleResult, ctx.visitData);
-        continue;
-      }
-
-      const itemDiff = diff(item, itemResult);
-      if (hasItems(itemDiff)) {
-        ctx.logger.info({
-          diff: itemDiff,
-          item,
-          rule: rule.name,
-        }, 'rule passed with modifications');
-
-        if (ctx.schemaOptions.mutate) {
-          applyDiff(item, itemResult);
-        }
-      } else {
-        ctx.logger.info({ rule: rule.name }, 'rule passed');
-      }
-
-      itemIndex += 1;
-    }
-  }
-
-  return ctx;
-}

test/rule/TestRule.ts

@@ -2,7 +2,8 @@ import { expect } from 'chai';
 import { LogLevel, NullLogger } from 'noicejs';
 import { mock, spy, stub } from 'sinon';
 
-import { createRuleSelector, createRuleSources, resolveRules, visitRules } from '../../src/rule';
+import { createRuleSelector, createRuleSources, resolveRules } from '../../src/rule';
+import { RuleVisitor } from '../../src/rule/RuleVisitor';
 import { SchemaRule } from '../../src/rule/SchemaRule';
 import { VisitorContext } from '../../src/visitor/VisitorContext';
 import { describeLeaks, itLeaks } from '../helpers/async';
@@ -128,7 +129,10 @@ describeLeaks('rule visitor', async () => {
     pickStub.onFirstCall().returns(Promise.resolve([]));
     pickStub.throws();
 
-    await visitRules(ctx, [rule], {});
+    const visitor = new RuleVisitor({
+      rules: [rule],
+    });
+    await visitor.visit(ctx, {});
 
     mockRule.verify();
     expect(ctx.errors.length).to.equal(0);
@@ -163,7 +167,10 @@ describeLeaks('rule visitor', async () => {
     visitStub.onFirstCall().returns(Promise.resolve(ctx));
     visitStub.throws();
 
-    await visitRules(ctx, [rule], {});
+    const visitor = new RuleVisitor({
+      rules: [rule],
+    });
+    await visitor.visit(ctx, {});
 
     mockRule.verify();
     expect(ctx.errors.length).to.equal(0);
@@ -196,7 +203,10 @@ describeLeaks('rule visitor', async () => {
       errors: [],
     }));
 
-    await visitRules(ctx, [rule], data);
+    const visitor = new RuleVisitor({
+      rules: [rule],
+    });
+    await visitor.visit(ctx, data);
 
     expect(pickSpy).to.have.callCount(1).and.to.have.been.calledWithExactly(ctx, data);
     expect(visitStub).to.have.callCount(3);
@@ -232,7 +242,10 @@ describeLeaks('rule visitor', async () => {
       }],
     }));
 
-    await visitRules(ctx, [rule], data);
+    const visitor = new RuleVisitor({
+      rules: [rule],
+    });
+    await visitor.visit(ctx, data);
 
     expect(visitStub).to.have.callCount(3);
     expect(ctx.errors.length).to.equal(3);