1 files changed, 171 insertions, 0 deletions
diff --git a/devtools/client/framework/test/metrics/head.js b/devtools/client/framework/test/metrics/head.js
new file mode 100644
index 0000000000..0246190b31
--- /dev/null
+++ b/devtools/client/framework/test/metrics/head.js
@@ -0,0 +1,171 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+// shared-head.js handles imports, constants, and utility functions
+Services.scriptloader.loadSubScript(
+  "chrome://mochitests/content/browser/devtools/client/shared/test/shared-head.js",
+  this
+);
+
+// So that PERFHERDER data can be extracted from the logs.
+SimpleTest.requestCompleteLog();
+
+function getFilteredModules(filters, loaders) {
+  let modules = [];
+  for (const l of loaders) {
+    const loaderModulesMap = l.modules;
+    const loaderModulesPaths = Object.keys(loaderModulesMap);
+    modules = modules.concat(loaderModulesPaths);
+  }
+  return modules.filter(url => filters.some(filter => url.includes(filter)));
+}
+
+function countCharsInModules(modules) {
+  return modules.reduce((sum, uri) => {
+    try {
+      return sum + require("raw!" + uri).length;
+    } catch (e) {
+      // Ignore failures
+      return sum;
+    }
+  }, 0);
+}
+
+/**
+ * Record module loading data.
+ *
+ * @param {Object}
+ * - filterString {String} path to use to filter modules specific to the current panel
+ * - loaders {Array} Array of Loaders to check for modules
+ * - panelName {String} reused in identifiers for perfherder data
+ */
+function runMetricsTest({ filterString, loaders, panelName }) {
+  const allModules = getFilteredModules([""], loaders);
+  const panelModules = getFilteredModules([filterString], loaders);
+  const vendoredModules = getFilteredModules(
+    ["devtools/client/debugger/dist/vendors", "devtools/client/shared/vendor/"],
+    loaders
+  );
+
+  const allModulesCount = allModules.length;
+  const panelModulesCount = panelModules.length;
+  const vendoredModulesCount = vendoredModules.length;
+
+  const allModulesChars = countCharsInModules(allModules);
+  const panelModulesChars = countCharsInModules(panelModules);
+  const vendoredModulesChars = countCharsInModules(vendoredModules);
+
+  const PERFHERDER_DATA = {
+    framework: {
+      name: "devtools",
+    },
+    suites: [
+      {
+        name: panelName + "-metrics",
+        value: allModulesChars,
+        subtests: [
+          {
+            name: panelName + "-modules",
+            value: panelModulesCount,
+          },
+          {
+            name: panelName + "-chars",
+            value: panelModulesChars,
+          },
+          {
+            name: "all-modules",
+            value: allModulesCount,
+          },
+          {
+            name: "all-chars",
+            value: allModulesChars,
+          },
+          {
+            name: "vendored-modules",
+            value: vendoredModulesCount,
+          },
+          {
+            name: "vendored-chars",
+            value: vendoredModulesChars,
+          },
+        ],
+      },
+    ],
+  };
+  info("PERFHERDER_DATA: " + JSON.stringify(PERFHERDER_DATA));
+
+  // Simply check that we found valid values.
+  ok(
+    allModulesCount > panelModulesCount && panelModulesCount > 0,
+    "Successfully recorded module count for " + panelName
+  );
+  ok(
+    allModulesChars > panelModulesChars && panelModulesChars > 0,
+    "Successfully recorded char count for " + panelName
+  );
+
+  // Easy way to check how many vendored chars we have for a given panel.
+  const percentage = ((100 * vendoredModulesChars) / allModulesChars).toFixed(
+    1
+  );
+  info(`Percentage of vendored chars for ${panelName}: ${percentage}%`);
+}
+
+function getDuplicatedModules(loaders) {
+  const allModules = getFilteredModules([""], loaders);
+
+  const uniqueModules = new Set();
+  const duplicatedModules = new Set();
+  for (const mod of allModules) {
+    if (uniqueModules.has(mod)) {
+      duplicatedModules.add(mod);
+    }
+
+    uniqueModules.add(mod);
+  }
+
+  return duplicatedModules;
+}
+
+/**
+ * Check that modules are only loaded once in a given set of loaders.
+ * Panels might load the same module twice by mistake if they are both using
+ * a BrowserLoader and the regular DevTools Loader.
+ *
+ * @param {Array} loaders
+ *        Array of Loader instances.
+ * @param {Array} allowedDupes
+ *        Array of Strings which are paths to known duplicated modules.
+ *        The test will also fail if a allowedDupesed module is not found in the
+ *        duplicated modules.
+ */
+function runDuplicatedModulesTest(loaders, allowedDupes) {
+  const duplicatedModules = getDuplicatedModules(loaders);
+
+  // Remove allowedDupes entries, and fail if an allowed entry is not found.
+  for (const mod of allowedDupes) {
+    const deleted = duplicatedModules.delete(mod);
+    if (!deleted) {
+      ok(
+        false,
+        "module not found in the duplicated modules: [" +
+          mod +
+          "]. The allowedDupes array should be updated to remove it."
+      );
+    }
+  }
+
+  // Prepare a log string with the paths of all duplicated modules.
+  let duplicatedModulesLog = "";
+  for (const mod of duplicatedModules) {
+    duplicatedModulesLog += `  [duplicated module] ${mod}\n`;
+  }
+
+  // Check that duplicatedModules Set is empty.
+  is(
+    duplicatedModules.size,
+    0,
+    "Duplicated module load detected. List of duplicated modules:\n" +
+      duplicatedModulesLog
+  );
+}