docs: show browser test stats in the readme (#24)

README.md

@@ -1,3 +1,9 @@
+# Browser Test Stats
+<!-- GEN:test-stats -->
+|Firefox|Chromium|WebKit|all|
+|---|---|---|---|
+|511/650|698/705|325/653|309/650|
+<!-- GEN:stop -->
 
 # Contributing
 

test/stats.js

@@ -0,0 +1,69 @@
+const path = require('path');
+const {TestRunner} = require('../utils/testrunner/');
+const utils = require('./utils');
+const {addTests} = require('./playwright.spec.js');
+const firefoxTests = testsForProduct('Firefox');
+const chromiumTests = testsForProduct('Chromium');
+const webkitTests = testsForProduct('WebKit');
+const goalSuite = intersectSets(firefoxTests.all, chromiumTests.all, webkitTests.all);
+const skippedSuite = intersectSets(goalSuite, joinSets(firefoxTests.skipped, chromiumTests.skipped, webkitTests.skipped));
+
+module.exports = {
+  firefox: {
+    total: firefoxTests.all.size,
+    skipped: firefoxTests.skipped.size,
+  },
+  chromium: {
+    total: chromiumTests.all.size,
+    skipped: chromiumTests.skipped.size,
+  },
+  webkit: {
+    total: webkitTests.all.size,
+    skipped: webkitTests.skipped.size,
+  },
+  all: {
+    total: goalSuite.size,
+    skipped: skippedSuite.size,
+  }
+};
+
+/**
+ * @param {string} product 
+ */
+function testsForProduct(product) {
+  const testRunner = new TestRunner();
+  addTests({
+    product,
+    playwrightPath: path.join(utils.projectRoot(), `${product.toLowerCase()}.js`),
+    testRunner
+  });
+  return {
+    all: new Set(testRunner.tests().map(test => test.fullName)),
+    skipped: new Set(testRunner.tests().filter(test => test.declaredMode === 'skip').map(test => test.fullName))
+  }
+}
+
+/**
+ * @param  {...Set} sets 
+ */
+function intersectSets(...sets) {
+  if (!sets.length)
+    return new Set();
+  const intersect = new Set();
+  const [first, ...rest] = sets;
+  outer: for (const item of first) {
+    for (const set of rest)
+      if (!set.has(item))
+        continue outer;
+    intersect.add(item);
+  }
+  return intersect;
+}
+
+function joinSets(...sets) {
+  const joined = new Set();
+  for (const set of sets)
+    for (const item of set)
+      joined.add(item);
+  return joined;
+}

utils/doclint/preprocessor/index.js

@@ -70,6 +70,8 @@ module.exports.runCommands = function(sources, version) {
       newText = isReleaseVersion ? '' : command.originalText;
     else if (command.name === 'toc')
       newText = generateTableOfContents(command.source.text().substring(command.to));
+    else if (command.name === 'test-stats')
+      newText = generateTestStats();
     if (newText === null)
       messages.push(Message.error(`Unknown command 'gen:${command.name}'`));
     else if (applyCommand(command, newText))
@@ -91,6 +93,19 @@ function applyCommand(command, editText) {
   return command.source.setText(newText);
 }
 
+function generateTestStats() {
+  const stats = require('../../../test/stats');
+  return `
+|Firefox|Chromium|WebKit|all|
+|---|---|---|---|
+|${s('firefox')}|${s('chromium')}|${s('webkit')}|${s('all')}|
+`;
+  function s(product) {
+    const {total, skipped} = stats[product];
+    return `${total-skipped}/${total}`;
+  }
+}
+
 function generateTableOfContents(mdText) {
   const ids = new Set();
   const titles = [];