CHANGE @W-20773111@ - Perf test for run rules (#400)

Author: aruntyagiTutu

packages/code-analyzer-eslint-engine/test/perf-eslint-run.test.ts

@@ -0,0 +1,92 @@
+import {Engine, RuleDescription, Workspace} from "@salesforce/code-analyzer-engine-api";
+import {ESLintEnginePlugin} from "../src";
+import {DEFAULT_CONFIG, ESLintEngineConfig} from "../src/config";
+import {createDescribeOptions, createRunOptions} from "./test-helpers";
+
+/**
+ * One-off performance probe for running ESLint rules (runRules).
+ *
+ * What this test does:
+ * - Instantiates the ESLint engine with the current base configuration.
+ * - Discovers rules (describeRules), then selects a subset to run (e.g., Recommended).
+ * - Runs the engine against the provided workspace (PERF_WS must be set).
+ * - Samples Node's resident set size (RSS) and prints a JSON summary:
+ *     {
+ *       "files_scanned": <unique files that produced violations>,
+ *       "rules_run": <number of rules executed>,
+ *       "run_ms": <wall time in milliseconds for runRules>,
+ *       "peak_rss_mb": <approximate peak memory (MB) observed during the run>,
+ *       "violations": <total violations found>
+ *     }
+ *
+ * How to run (skipped by default; opt-in with env var):
+ *   ESLINT_ENGINE_PERF_RUN=true PERF_WS="/absolute/path/to/project" PERF_DISCOVER=true \
+ *   npm run test-typescript -- packages/code-analyzer-eslint-engine/test/perf-eslint-run.test.ts
+ *
+ * Optional env vars:
+ * - PERF_RULES_LIMIT=200  → cap the number of rules to run (keeps runtime stable)
+ * - PERF_DISCOVER=true    → let ESLint auto-discover configs from PERF_WS (sets config_root to PERF_WS)
+ * - You can toggle:
+ *     // disable_react_base_config: true,
+ *     // disable_typescript_base_config: true,
+ *   in the config below to attribute parser/plugin costs.
+ */
+const RUN = process.env.ESLINT_ENGINE_PERF_RUN === 'true';
+(RUN ? describe : describe.skip)('ESLint engine perf (runRules one-off)', () => {
+    it('measures runRules wall time and peak RSS', async () => {
+        const cfg: ESLintEngineConfig = {
+            ...DEFAULT_CONFIG,
+            // Toggle to isolate costs if desired:
+            disable_react_base_config: false,
+            disable_typescript_base_config: true,
+            config_root: __dirname,
+            auto_discover_eslint_config: process.env.PERF_DISCOVER === 'true',
+        };
+
+        const wsPath = process.env.PERF_WS;
+        if (!wsPath) {
+            throw new Error('PERF_WS env var must be set to an absolute path for runRules perf test.');
+        }
+        const ws: Workspace = new Workspace('perf', [wsPath]);
+        if (process.env.PERF_DISCOVER === 'true') {
+            cfg.config_root = wsPath;
+        }
+
+        const engine: Engine = await new ESLintEnginePlugin().createEngine('eslint', cfg);
+
+        // Discover and select rules to run (Recommended by default), with an optional cap.
+        const discovered: RuleDescription[] = await engine.describeRules(createDescribeOptions(ws));
+        const rulesToRun: string[] = discovered
+            .filter(r => r.tags.includes('Recommended'))
+            .slice(0, Number(process.env.PERF_RULES_LIMIT) || 200)
+            .map(r => r.name);
+
+        const peak = {rss: 0};
+        const sampler = setInterval(() => {
+            const m = process.memoryUsage();
+            if (m.rss > peak.rss) peak.rss = m.rss;
+        }, 50);
+
+        const mem0 = process.memoryUsage().rss;
+        const t0 = performance.now();
+        const results = await engine.runRules(rulesToRun, createRunOptions(ws));
+        const t1 = performance.now();
+        const mem1 = process.memoryUsage().rss;
+        clearInterval(sampler);
+
+        // Calculate files that produced violations (as a proxy for scanned footprint).
+        const filesScanned = Array.from(new Set(results.violations.map(v => v.codeLocations[0].file))).length;
+
+        // eslint-disable-next-line no-console
+        console.log(JSON.stringify({
+            files_scanned: filesScanned,
+            rules_run: rulesToRun.length,
+            run_ms: Math.round(t1 - t0),
+            peak_rss_mb: Math.round(Math.max(peak.rss, mem0, mem1) / (1024 * 1024)),
+            violations: results.violations.length
+        }, null, 2));
+
+        expect(rulesToRun.length).toBeGreaterThan(0);
+    });
+});
+