code coverage POC

.gitignore

@@ -89,3 +89,6 @@ test.tap
 # Xcode workspaces and project folders
 *.xcodeproj
 *.xcworkspace
+/coverage
+/lib-cov
+node.gyp.orig

Makefile

@@ -610,6 +610,15 @@ jslint-ci:
 	$(NODE) tools/jslint.js -f tap -o test-eslint.tap benchmark lib src test \
 	  tools/doc tools/eslint-rules tools/jslint.js
 
+cover:
+	@mkdir -p coverage/
+	bash tools/coverage/patch-node-gyp.sh
+	./configure
+	@istanbul instrument --output lib-cov/ ./lib/
+
+cover-test: cover
+	bash tools/coverage/run-tests.sh
+
 CPPLINT_EXCLUDE ?=
 CPPLINT_EXCLUDE += src/node_lttng.cc
 CPPLINT_EXCLUDE += src/node_root_certs.h

test/common.js

@@ -325,6 +325,10 @@ if (global.Symbol) {
   knownGlobals.push(Symbol);
 }
 
+if (process.env.CORE_COVERAGE && global.__coverage__) {
+  knownGlobals.push(__coverage__);
+}
+
 function leakedGlobals() {
   var leaked = [];
 
@@ -337,9 +341,21 @@ function leakedGlobals() {
 exports.leakedGlobals = leakedGlobals;
 
 // Turn this off if the test should not check for global leaks.
-exports.globalCheck = true;
+exports.globalCheck = !process.env.CORE_COVERAGE;
 
 process.on('exit', function() {
+  if (process.env.CORE_COVERAGE) {
+    const path = require('path');
+    const fs = require('fs');
+    const testName = path.basename(require.main.filename);
+    const covDir = path.join(__dirname, '..', 'coverage', testName);
+    try {
+      fs.mkdirSync(covDir);
+    } catch (err) {}
+    fs.writeFileSync(path.join(covDir, 'coverage.json'),
+                     JSON.stringify(global.__coverage__),
+                     'utf8');
+  }
   if (!exports.globalCheck) return;
   var leaked = leakedGlobals();
   if (leaked.length > 0) {

tools/coverage/patch-node-gyp.sh

@@ -0,0 +1,14 @@
+#!/bin/bash
+
+set -e
+
+cd $(dirname $0)/../..
+
+if grep -q "lib-cov/internal/bootstrap_node.js" node.gyp; then
+  echo "node.gyp already updated...skipping"
+  exit 0
+fi
+
+sed -i ".orig" "s/'lib\//'lib-cov\//" node.gyp
+
+echo "successfully updated node.gyp"

tools/coverage/run-tests.sh

@@ -0,0 +1,11 @@
+#!/bin/bash
+
+set -e
+
+cd $(dirname $0)/../..
+
+make test CORE_COVERAGE=1 || echo "Test suite failed with coverage."
+
+echo "Generating coverage reports. This may take a bit."
+
+istanbul report