[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

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[];
   }
 }

packages/opencensus-core/src/resource/resource.ts

@@ -65,9 +65,10 @@ export class CoreResource {
    * @returns {Resource} The resource.
    */
   static mergeResources(resources: Resource[]): Resource {
-    let currentResource: Resource;
-    for (const resource of resources) {
-      currentResource = this.merge(currentResource, resource);
+    if (resources.length === 0) return {type: 'global', labels: {}};
+    let currentResource = resources[0];
+    for (let i = 1; i < resources.length; i++) {
+      currentResource = this.merge(currentResource, resources[i]);
     }
     return currentResource;
   }
@@ -81,14 +82,12 @@ export class CoreResource {
    * @param  {string} rawEnvType The resource type.
    * @returns {string} The sanitized resource type.
    */
-  private static parseResourceType(rawEnvType: string): string {
-    if (rawEnvType) {
-      if (!CoreResource.isValidAndNotEmpty(rawEnvType)) {
-        throw new Error(`Type ${CoreResource.ERROR_MESSAGE_INVALID_CHARS}`);
-      }
-      return rawEnvType.trim();
+  private static parseResourceType(rawEnvType?: string): string|null {
+    if (!rawEnvType) return null;
+    if (!CoreResource.isValidAndNotEmpty(rawEnvType)) {
+      throw new Error(`Type ${CoreResource.ERROR_MESSAGE_INVALID_CHARS}`);
     }
-    return null;
+    return rawEnvType.trim();
   }
 
   /**
@@ -103,30 +102,30 @@ export class CoreResource {
    * of key/value pairs.
    * @returns {Labels} The sanitized resource labels.
    */
-  private static parseResourceLabels(rawEnvLabels: string): Labels {
+  private static parseResourceLabels(rawEnvLabels?: string): Labels {
+    if (!rawEnvLabels) return {};
+
     const labels: Labels = {};
-    if (rawEnvLabels) {
-      const rawLabels: string[] = rawEnvLabels.split(this.COMMA_SEPARATOR, -1);
-      for (const rawLabel of rawLabels) {
-        const keyValuePair: string[] =
-            rawLabel.split(this.LABEL_KEY_VALUE_SPLITTER, -1);
-        if (keyValuePair.length !== 2) {
-          continue;
-        }
-        let [key, value] = keyValuePair;
-        // Leading and trailing whitespaces are trimmed.
-        key = key.trim();
-        value = value.trim().split('^"|"$').join('');
-        if (!CoreResource.isValidAndNotEmpty(key)) {
-          throw new Error(
-              `Label key ${CoreResource.ERROR_MESSAGE_INVALID_CHARS}`);
-        }
-        if (!CoreResource.isValid(value)) {
-          throw new Error(
-              `Label value ${CoreResource.ERROR_MESSAGE_INVALID_VALUE}`);
-        }
-        labels[key] = value;
+    const rawLabels: string[] = rawEnvLabels.split(this.COMMA_SEPARATOR, -1);
+    for (const rawLabel of rawLabels) {
+      const keyValuePair: string[] =
+          rawLabel.split(this.LABEL_KEY_VALUE_SPLITTER, -1);
+      if (keyValuePair.length !== 2) {
+        continue;
+      }
+      let [key, value] = keyValuePair;
+      // Leading and trailing whitespaces are trimmed.
+      key = key.trim();
+      value = value.trim().split('^"|"$').join('');
+      if (!CoreResource.isValidAndNotEmpty(key)) {
+        throw new Error(
+            `Label key ${CoreResource.ERROR_MESSAGE_INVALID_CHARS}`);
+      }
+      if (!CoreResource.isValid(value)) {
+        throw new Error(
+            `Label value ${CoreResource.ERROR_MESSAGE_INVALID_VALUE}`);
       }
+      labels[key] = value;
     }
     return labels;
   }
@@ -173,7 +172,7 @@ export class CoreResource {
    * @returns {boolean} Whether the String is valid and not empty.
    */
   private static isValidAndNotEmpty(name: string): boolean {
-    return name && name.length > 0 && CoreResource.isValid(name);
+    return name.length > 0 && CoreResource.isValid(name);
   }
 
   /** TEST_ONLY */

packages/opencensus-core/src/resource/types.ts

@@ -19,7 +19,7 @@ export interface Resource {
   /**
    * An optional string which describes a well-known type of resource.
    */
-  readonly type: string;
+  readonly type: string|null;
 
   /**
    * A dictionary of labels with string keys and values that provide information

packages/opencensus-core/src/stats/bucket-boundaries.ts

@@ -52,16 +52,18 @@ export class BucketBoundaries {
   private dropNegativeBucketBounds(bucketBoundaries: number[]): Bucket[] {
     let negative = 0;
     if (!bucketBoundaries) return [];
-    const result = bucketBoundaries.reduce((accumulator, boundary, index) => {
-      if (boundary > 0) {
-        const nextBoundary = bucketBoundaries[index + 1];
-        this.validateBoundary(boundary, nextBoundary);
-        accumulator.push(boundary);
-      } else {
-        negative++;
-      }
-      return accumulator;
-    }, []);
+    const result = bucketBoundaries.reduce(
+        (accumulator: number[], boundary: number, index: number) => {
+          if (boundary > 0) {
+            const nextBoundary = bucketBoundaries[index + 1];
+            this.validateBoundary(boundary, nextBoundary);
+            accumulator.push(boundary);
+          } else {
+            negative++;
+          }
+          return accumulator;
+        },
+        []);
     if (negative) {
       this.logger.warn(`Dropping ${
           negative} negative bucket boundaries, the values must be strictly > 0.`);
@@ -95,4 +97,4 @@ export class BucketBoundaries {
       }
     }
   }
-}
+}

packages/opencensus-core/src/stats/metric-utils.ts

@@ -78,7 +78,7 @@ export class MetricUtils {
    * @param tagValues
    * @returns {LabelValue[]} List of label values
    */
-  static tagValuesToLabelValues(tagValues: TagValue[]): LabelValue[] {
+  static tagValuesToLabelValues(tagValues: Array<TagValue|null>): LabelValue[] {
     return tagValues.map(
         (tagValue) => ({value: tagValue ? tagValue.value : null}));
   }

packages/opencensus-core/src/stats/recorder.ts

@@ -17,7 +17,7 @@
 import {TagKey, TagValue} from '../tags/types';
 import {AggregationData, AggregationType, CountData, DistributionData, LastValueData, Measurement, MeasureType, SumData} from './types';
 
-const UNKNOWN_TAG_VALUE: TagValue = null;
+const UNKNOWN_TAG_VALUE: TagValue|null = null;
 
 export class Recorder {
   static addMeasurement(
@@ -45,7 +45,7 @@ export class Recorder {
 
   /** Gets the tag values from tags and columns */
   static getTagValues(tags: Map<TagKey, TagValue>, columns: TagKey[]):
-      TagValue[] {
+      Array<TagValue|null> {
     return columns.map(
         (tagKey) =>
             (tags.get(tagKey) ||
@@ -63,7 +63,11 @@ export class Recorder {
     if (bucketIndex < 0) {
       bucketIndex = distributionData.buckets.length;
     }
-    distributionData.bucketCounts[bucketIndex] += 1;
+
+    if (distributionData.bucketCounts &&
+        distributionData.bucketCounts.length > bucketIndex) {
+      distributionData.bucketCounts[bucketIndex] += 1;
+    }
 
     if (distributionData.count === 1) {
       distributionData.mean = value;
@@ -82,7 +86,8 @@ export class Recorder {
 
     // No implicit recording for exemplars - if there are no attachments
     // (contextual information), don't record exemplars.
-    if (attachments) {
+    if (attachments && distributionData.exemplars &&
+        distributionData.exemplars.length > bucketIndex) {
       distributionData.exemplars[bucketIndex] = {
         value,
         timestamp: distributionData.timestamp,

packages/opencensus-core/src/stats/types.ts

@@ -189,7 +189,7 @@ export interface View {
   /**
    * The end time for this view - represents the last time a value was recorded
    */
-  endTime: number;
+  endTime?: number;
   /** true if the view was registered */
   registered: boolean;
   /**
@@ -233,7 +233,7 @@ export interface AggregationMetadata {
   /** The aggregation type of the aggregation data */
   readonly type: AggregationType;
   /** The tagValues that this AggregationData collects and aggregates */
-  readonly tagValues: TagValue[];
+  readonly tagValues: Array<TagValue|null>;
   /** The latest timestamp a new data point was recorded */
   timestamp: number;
 }