[Core] Enforce strictNullChecks (#453)

* Enforce null check on [core] package

* fix review comments

1. Assign default value to parentSpanId and name.
2. Assign default value({}) to activeTraceParams.
3. Add traceState back for no-record-span-base

* Add NoopLogger class

* Use map and filter instread of loop + added TODO

* Remove  and fix comment

* Change TraceState = string|undefined -> TraceState = string

* Fix build

Author: mayurkale22

CHANGELOG.md

@@ -23,6 +23,7 @@ All notable changes to this project will be documented in this file.
 - Add support for recording Exemplars.
 - Add `TagMetadata` that defines the properties associated with a `Tag`.
 - Add HTTP text format serializer to Tag propagation component.
+- Enforce `--strictNullChecks` and `--noUnusedLocals` Compiler Options on [opencensus-core] package.
 
 ## 0.0.9 - 2019-02-12
 - Add Metrics API.

packages/opencensus-core/src/common/console-logger.ts

@@ -25,7 +25,7 @@ const logDriver = require('log-driver');
 export class ConsoleLogger implements types.Logger {
   private logger: typeof logDriver;
   static LEVELS = ['silent', 'error', 'warn', 'info', 'debug'];
-  level: string;
+  level?: string;
 
   /**
    * Constructs a new ConsoleLogger instance
@@ -45,7 +45,7 @@ export class ConsoleLogger implements types.Logger {
     } else {
       opt = options || {};
     }
-    this.level = opt.level;
+    if (opt.level) this.level = opt.level;
     this.logger =
         logDriver({levels: ConsoleLogger.LEVELS, level: opt.level || 'silent'});
   }

packages/opencensus-core/src/common/noop-logger.ts

@@ -0,0 +1,31 @@
+/**
+ * Copyright 2019, OpenCensus Authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+import {Logger} from './types';
+
+/** No-op implementation of Logger */
+class NoopLogger implements Logger {
+  // tslint:disable-next-line:no-any
+  debug(message: string, ...args: any[]) {}
+  // tslint:disable-next-line:no-any
+  error(...args: any[]) {}
+  // tslint:disable-next-line:no-any
+  warn(...args: any[]) {}
+  // tslint:disable-next-line:no-any
+  info(...args: any[]) {}
+}
+
+export const noopLogger = new NoopLogger();

packages/opencensus-core/src/exporters/console-exporter.ts

@@ -24,7 +24,7 @@ import * as types from './types';
 
 /** Do not send span data */
 export class NoopExporter implements types.Exporter {
-  logger: loggerTypes.Logger;
+  logger?: loggerTypes.Logger;
   onStartSpan(root: modelTypes.RootSpan) {}
   onEndSpan(root: modelTypes.RootSpan) {}
   publish(rootSpans: modelTypes.RootSpan[]) {
@@ -36,7 +36,7 @@ export class NoopExporter implements types.Exporter {
 export class ConsoleExporter implements types.Exporter {
   /** Buffer object to store the spans. */
   // @ts-ignore
-  private logger: loggerTypes.Logger;
+  private logger?: loggerTypes.Logger;
   private buffer: ExporterBuffer;
 
   /**

packages/opencensus-core/src/exporters/exporter-buffer.ts

@@ -20,6 +20,8 @@ import * as configTypes from '../trace/config/types';
 import * as modelTypes from '../trace/model/types';
 import * as types from './types';
 
+const DEFAULT_BUFFER_SIZE = 100;
+const DEFAULT_BUFFER_TIMEOUT = 20000;
 
 /** Controls the sending of traces to exporters. */
 export class ExporterBuffer {
@@ -46,8 +48,12 @@ export class ExporterBuffer {
   constructor(exporter: types.Exporter, config: configTypes.BufferConfig) {
     this.exporter = exporter;
     this.logger = config.logger || logger.logger();
-    this.bufferSize = config.bufferSize;
-    this.bufferTimeout = config.bufferTimeout;
+    this.bufferSize = isNaN(Number(config.bufferSize)) ?
+        DEFAULT_BUFFER_SIZE :
+        Number(config.bufferSize);
+    this.bufferTimeout = isNaN(Number(config.bufferTimeout)) ?
+        DEFAULT_BUFFER_TIMEOUT :
+        Number(config.bufferTimeout);
     return this;
   }
 

packages/opencensus-core/src/internal/clock.ts

@@ -26,7 +26,7 @@ export class Clock {
   /** The time in high resolution in a [seconds, nanoseconds]. */
   private hrtimeLocal: [number, number];
   /** The duration between start and end of the clock. */
-  private diff: [number, number] = null;
+  private diff: [number, number] = [0, 0];
 
   /** Constructs a new SamplerImpl instance. */
   constructor() {
@@ -46,7 +46,7 @@ export class Clock {
   /** Gets the duration of the clock. */
   get duration(): number {
     if (!this.endedLocal) {
-      return null;
+      return 0;
     }
     const ns = this.diff[0] * 1e9 + this.diff[1];
     return ns / 1e6;
@@ -63,11 +63,10 @@ export class Clock {
    * @returns A Date object with the current duration.
    */
   get endTime(): Date {
-    let result: Date = null;
     if (this.ended) {
-      result = new Date(this.startTime.getTime() + this.duration);
+      return new Date(this.startTime.getTime() + this.duration);
     }
-    return result;
+    return new Date();
   }
 
   /** Indicates if the clock was ended. */

packages/opencensus-core/src/metrics/gauges/derived-gauge.ts

@@ -72,7 +72,7 @@ export class DerivedGauge implements types.Meter {
   private metricDescriptor: MetricDescriptor;
   private labelKeysLength: number;
   private registeredPoints: Map<string, GaugeEntry> = new Map();
-  private extractor: ValueExtractor;
+  private extractor?: ValueExtractor;
 
   private static readonly LABEL_VALUE = 'labelValue';
   private static readonly LABEL_VALUES = 'labelValues';
@@ -201,7 +201,7 @@ export class DerivedGauge implements types.Meter {
    *
    * @returns {Metric} The Metric.
    */
-  getMetric(): Metric {
+  getMetric(): Metric|null {
     if (this.registeredPoints.size === 0) {
       return null;
     }

packages/opencensus-core/src/metrics/gauges/gauge.ts

@@ -110,7 +110,7 @@ export class Gauge implements types.Meter {
     const hash = hashLabelValues(labelValues);
     // return if the specified labelValues is already associated with the point.
     if (this.registeredPoints.has(hash)) {
-      return this.registeredPoints.get(hash);
+      return this.registeredPoints.get(hash)!;
     }
     if (this.labelKeysLength !== labelValues.length) {
       throw new Error(Gauge.ERROR_MESSAGE_INVALID_SIZE);
@@ -126,7 +126,7 @@ export class Gauge implements types.Meter {
    *
    * @returns {Metric} The Metric.
    */
-  getMetric(): Metric {
+  getMetric(): Metric|null {
     if (this.registeredPoints.size === 0) {
       return null;
     }

packages/opencensus-core/src/metrics/gauges/types.ts

@@ -22,7 +22,7 @@ export interface Meter {
    *
    * @returns {Metric} The Metric.
    */
-  getMetric(): Metric;
+  getMetric(): Metric|null;
 }
 
 export interface Point {

packages/opencensus-core/src/metrics/metric-registry.ts

@@ -198,7 +198,8 @@ class MetricProducerForRegistry extends BaseMetricProducer {
    * @returns {Metric[]} The list of metrics.
    */
   getMetrics(): Metric[] {
-    return Array.from(
-        this.registeredMetrics, ([_, meter]) => meter.getMetric());
+    return Array.from(this.registeredMetrics.values())
+               .map(meter => meter.getMetric())
+               .filter(meter => !!meter) as Metric[];
   }
 }