add perf tests, fixes #1053 (#1054)

test/perf-test.js

@@ -0,0 +1,59 @@
+/* eslint-disable no-console */
+/**
+ * Performance Tests
+ *
+ * This file measures the performance of renderToString using a number of strings
+ * from ss_data.yaml.
+ *
+ * TODO:
+ * - allow users to specify a different key or keys from ss_data.yaml
+ * - allow users to specify a different string or strings
+ * - provide a way to test the performance against different branches
+ */
+require('babel-register');
+const Benchmark = require('benchmark');
+const yaml = require('js-yaml');
+const fs = require('fs');
+const path = require('path');
+
+const filename = path.resolve(__dirname, 'screenshotter/ss_data.yaml');
+const data = yaml.load(fs.readFileSync(filename, 'utf-8'));
+
+console.log('compiling katex...');
+const katex = require('../katex').default;
+console.log('');
+
+// Benchmark is a performancing testing library.  It allows you to define a
+// suite of tests.  After adding tests to the suite with the .add() method they
+// can be run by calling the .run() method.  See https://benchmarkjs.com.
+const suite = new Benchmark.Suite;
+
+const testsToRun = [
+    "AccentsText",
+    "ArrayMode",
+    "GroupMacros",
+    "MathBb",
+    "SqrtRoot",
+    "StretchyAccent",
+    "Units",
+];
+
+for (const key of testsToRun) {
+    const value = data[key];
+    if (typeof value === "string") {
+        suite.add(key, () => katex.renderToString(value));
+    } else {
+        const options = {
+            macros: value.macros,
+        };
+        suite.add(key, () => katex.renderToString(value.tex, options));
+    }
+}
+
+// Print out the ops/sec for each test
+suite.on('cycle', function(event) {
+    console.log(String(event.target));
+});
+
+const config = {};
+suite.run(config);