SQUASH: generate process tree using processinfo index

Also, remove some unnecessary fields from process infos

bin/wrap.js

@@ -8,7 +8,7 @@ config.isChildProcess = true
 config._processInfo = {
   pid: process.pid,
   ppid: process.ppid,
-  parent: process.env.NYC_PROCESS_ID,
+  parent: process.env.NYC_PROCESS_ID || null,
   root: process.env.NYC_ROOT_ID
 }
 if (process.env.NYC_PROCESSINFO_EXTERNAL_ID) {

index.js

@@ -458,9 +458,7 @@ NYC.prototype.writeProcessIndex = function () {
   // build the actual index!
   const index = infos.reduce((index, info) => {
     index.processes[info.uuid] = {}
-    if (info.parent) {
-      index.processes[info.uuid].parent = info.parent
-    }
+    index.processes[info.uuid].parent = info.parent
     if (info.externalId) {
       if (index.externalIds[info.externalId]) {
         throw new Error(`External ID ${info.externalId} used by multiple processes`)
@@ -526,19 +524,25 @@ NYC.prototype._checkCoverage = function (summary, thresholds, file) {
 }
 
 NYC.prototype._loadProcessInfos = function () {
-  var _this = this
-  var files = fs.readdirSync(this.processInfoDirectory())
-
-  return files.filter(f => f !== 'index.json').map(function (f) {
+  return fs.readdirSync(this.processInfoDirectory()).map(f => {
+    let data
     try {
-      return new ProcessInfo(JSON.parse(fs.readFileSync(
-        path.resolve(_this.processInfoDirectory(), f),
+      data = JSON.parse(fs.readFileSync(
+        path.resolve(this.processInfoDirectory(), f),
         'utf-8'
-      )))
+      ))
     } catch (e) { // handle corrupt JSON output.
-      return {}
+      return null
     }
-  })
+    if (f !== 'index.json') {
+      data.nodes = []
+      data = new ProcessInfo(data)
+    }
+    return { file: path.basename(f, '.json'), data: data }
+  }).filter(Boolean).reduce((infos, info) => {
+    infos[info.file] = info.data
+    return infos
+  }, {})
 }
 
 NYC.prototype.eachReport = function (filenames, iterator, baseDirectory) {

lib/process.js

@@ -40,30 +40,19 @@ Object.defineProperty(ProcessInfo.prototype, 'label', {
 })
 
 ProcessInfo.buildProcessTree = function (infos) {
-  var treeRoot = new ProcessInfo({ _label: 'nyc', nodes: [] })
-  var nodes = { }
-
-  infos = infos.sort(function (a, b) {
-    return a.time - b.time
-  })
-
-  infos.forEach(function (p) {
-    p.nodes = []
-    nodes[p.root + ':' + p.pid] = p
-  })
-
-  infos.forEach(function (p) {
-    if (!p.ppid) {
-      return
+  const treeRoot = new ProcessInfo({ _label: 'nyc', nodes: [] })
+  const index = infos.index
+  for (const id in index.processes) {
+    const node = infos[id]
+    if (!node) {
+      throw new Error(`Invalid entry in processinfo index: ${id}`)
     }
-
-    var parent = nodes[p.root + ':' + p.ppid]
-    if (!parent) {
-      parent = treeRoot
+    const idx = index.processes[id]
+    node.nodes = idx.children.map(id => infos[id])
+    if (!node.parent) {
+      treeRoot.nodes.push(node)
     }
-
-    parent.nodes.push(p)
-  })
+  }
 
   return treeRoot
 }