refactor: address comments

src/cls-ah.ts

@@ -28,7 +28,7 @@ asyncHook.createHook({init, before, destroy}).enable();
 const EVENT_EMITTER_METHODS =
   [ 'addListener', 'on', 'once', 'prependListener', 'prependOncelistener' ];
 
-class Namespace implements CLSNamespace {
+class AsyncHooksNamespace implements CLSNamespace {
   get name(): string {
     throw new Error('Not implemented');
   }
@@ -98,7 +98,7 @@ class Namespace implements CLSNamespace {
   }
 }
 
-const namespace = new Namespace();
+const namespace = new AsyncHooksNamespace();
 
 // AsyncWrap Hooks
 

src/cls.ts

@@ -17,8 +17,11 @@
 'use strict';
 
 import * as semver from 'semver';
+import { SpanData } from './span-data';
 import * as CLS from 'continuation-local-storage';
 
+export type RootContext = SpanData | {} /* null span */ | null;
+
 const cls: typeof CLS = semver.satisfies(process.version, '>=8') &&
   process.env.GCLOUD_TRACE_NEW_CONTEXT ? require('./cls-ah')
                                        : require('continuation-local-storage');
@@ -37,7 +40,7 @@ export function getNamespace(): CLS.Namespace {
   return cls.getNamespace(TRACE_NAMESPACE);
 }
 
-export function getRootContext(): any {
+export function getRootContext(): RootContext {
   // First getNamespace check is necessary in case any
   // patched closures escaped before the agent was stopped and the
   // namespace was destroyed.
@@ -47,6 +50,6 @@ export function getRootContext(): any {
   return null;
 }
 
-export function setRootContext(rootContext: any): void {
+export function setRootContext(rootContext: RootContext): void {
   getNamespace().set('root', rootContext);
 }

src/trace-api.ts

@@ -196,7 +196,8 @@ TraceAgent.prototype.getCurrentContextId = function() {
   if (!rootSpan || rootSpan === nullSpan) {
     return null;
   }
-  return rootSpan.trace.traceId;
+  // TODO: When converting this file to TS, remove this cast.
+  return (rootSpan as SpanData).trace.traceId;
 };
 
 /**
@@ -220,7 +221,8 @@ TraceAgent.prototype.getWriterProjectId = function() {
  * @returns A new ChildSpan object, or null if there is no active root span.
  */
 TraceAgent.prototype.createChildSpan = function(options) {
-  var rootSpan = cls.getRootContext();
+  // TODO: When this file is converted to TS, remove this cast.
+  var rootSpan = cls.getRootContext() as SpanData | null;
   if (!rootSpan) {
     // Context was lost.
     this.logger_.warn(this.pluginName_ + ': Attempted to create child span ' +

src/tracing-policy.ts

@@ -17,11 +17,11 @@
 /**
  * An object that determines whether a request should be traced.
  */
-export interface Policy {
+export interface TracePolicy {
   shouldTrace(dateMillis: number, url: string): boolean;
 }
 
-export class RateLimiterPolicy implements Policy {
+export class RateLimiterPolicy implements TracePolicy {
   private traceWindow: number;
   private nextTraceStart: number;
 
@@ -42,9 +42,9 @@ export class RateLimiterPolicy implements Policy {
   }
 }
 
-export class FilterPolicy implements Policy {
+export class FilterPolicy implements TracePolicy {
   constructor(
-    private basePolicy: Policy,
+    private basePolicy: TracePolicy,
     private filterUrls: (string | RegExp)[]
   ) {}
 
@@ -60,13 +60,13 @@ export class FilterPolicy implements Policy {
   }
 }
 
-export class TraceAllPolicy implements Policy {
+export class TraceAllPolicy implements TracePolicy {
   shouldTrace() {
     return true;
   }
 }
 
-export class TraceNonePolicy implements Policy {
+export class TraceNonePolicy implements TracePolicy {
   shouldTrace() {
     return false;
   }
@@ -78,7 +78,7 @@ export interface TracePolicyOptions {
 }
 
 // TODO(kjin): This could be a class as well.
-export function createTracePolicy(config: TracePolicyOptions): Policy {
+export function createTracePolicy(config: TracePolicyOptions): TracePolicy {
   let basePolicy;
   if (config.samplingRate < 1) {
     basePolicy = new TraceAllPolicy();