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node_modules/@jet/environment/metrics/event-linter.js

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+"use strict";
+Object.defineProperty(exports, "__esModule", { value: true });
+exports.EventLinter = void 0;
+const object_reader_1 = require("../json/reader/object-reader");
+const optional_1 = require("../types/optional");
+const numerics = require("./helpers/numerics");
+/**
+ * A type which applies common business rules to metrics fields
+ * and generates events which are ready for posting to Figaro.
+ *
+ * The common business rules are:
+ * - Add base event fields provided by linter configuration provider object
+ * - Set clientBuiltType and resourceRevNum fields based on EventLinterEnvironment object values
+ * - Set xpSendMethod field to "jet-js"
+ * - Combine pageType and pageId using compound separator provided by linter configuration provider
+ *   and set result to "page" field.
+ * - Apply event field de-resolution rules provided by linter configuration provider object
+ * - Set the "position" field for events of "media" type.
+ */
+class EventLinter {
+    /**
+     * Create an event linter.
+     *
+     * @param options - The options which specify various behaviors of the new linter.
+     * This object will be frozen.
+     */
+    constructor(options) {
+        this.options = Object.freeze(options);
+    }
+    // MARK: Public Properties
+    /**
+     * Topic to use if an event fields blob does not specify one.
+     */
+    get defaultTopic() {
+        return this.options.defaultTopic;
+    }
+    // MARK: Utilities
+    /**
+     * Reduce the accuracy of fields in a blob according to
+     * a given array of rules provided by linter configuration object.
+     *
+     * @param eventFields - The fields of an event to reduce the accuracy of.
+     * @param rules - An array of de-resolution rules to apply to event fields.
+     */
+    applyDeResolutionRules(eventFields, rules) {
+        const eventFieldsReader = new object_reader_1.ObjectReader(eventFields);
+        for (const rule of rules) {
+            const value = eventFieldsReader.asNumber(rule.fieldName);
+            if ((0, optional_1.isNothing)(value)) {
+                continue;
+            }
+            let magnitude = rule.magnitude;
+            if ((0, optional_1.isNothing)(magnitude)) {
+                magnitude = 1024 * 1024;
+            }
+            let significantDigits = rule.significantDigits;
+            if ((0, optional_1.isNothing)(significantDigits)) {
+                significantDigits = 2;
+            }
+            if (magnitude <= 0.0 || significantDigits < 0.0) {
+                // This is the failure mode from MetricsKit.
+                eventFields[rule.fieldName] = Number.NaN;
+                continue;
+            }
+            const scaledValue = value / magnitude;
+            eventFields[rule.fieldName] = numerics.reduceSignificantDigits(scaledValue, significantDigits);
+        }
+    }
+    // MARK: Rules
+    /**
+     * Apply the rules which are universal to all metrics events
+     * to a given metrics fields linter.
+     *
+     * @param eventFields - The fields which will be used to construct a built event.
+     * @param topic - The topic the built event will be submitted to.
+     */
+    decorateCommonEventFields(eventFields, topic) {
+        const eventFieldsReader = new object_reader_1.ObjectReader(eventFields);
+        const configurationProvider = this.options.configuration;
+        // - Base metrics fields.
+        const baseFields = configurationProvider.baseFields(topic);
+        if ((0, optional_1.isSome)(baseFields)) {
+            Object.assign(eventFields, baseFields);
+        }
+        // - Universal basic fields.
+        eventFields["clientBuildType"] = this.options.environment.buildType;
+        eventFields["resourceRevNum"] = this.options.environment.jsVersion;
+        eventFields["xpSendMethod"] = "jet-js";
+        // - Page.
+        const pageType = eventFieldsReader.asString("pageType");
+        const pageId = eventFieldsReader.asString("pageId");
+        if ((0, optional_1.isSome)(pageType) && (0, optional_1.isSome)(pageId) && (0, optional_1.isNothing)(eventFields["page"])) {
+            const bagValue = configurationProvider.compoundSeparator(topic);
+            const separator = (0, optional_1.isSome)(bagValue) ? (0, optional_1.unwrapOptional)(bagValue) : "_";
+            eventFields["page"] = `${pageType}${separator}${pageId}`;
+        }
+        // - Field value resolution reduction.
+        const rules = configurationProvider.deResolutionRules(topic);
+        this.applyDeResolutionRules(eventFields, rules);
+    }
+    /**
+     * Apply the rules specific to the `media` event.
+     *
+     * @param eventFields - The fields which will be used to construct a built event.
+     */
+    decorateMediaEventEvents(eventFields) {
+        const eventFieldsReader = new object_reader_1.ObjectReader(eventFields);
+        const position = eventFieldsReader.asNumber("position");
+        if ((0, optional_1.isSome)(position)) {
+            eventFields["position"] = Math.round(position);
+        }
+    }
+    // MARK: Decorating Event Fields
+    /**
+     * Lint metrics event fields by applying the common business rules to a given fields blob.
+     *
+     * @remarks
+     *
+     * Note: A deep copy of event fields is created by linter using `JSON.parse(JSON.stringify(eventFields))`.
+     * The original event fields are not modified.
+     *
+     * @param eventFields - The fields to decorate.
+     * @param context - The additional event linter context to be passed to all
+     * event linter rules. This is a free-form object so clients can pass custom
+     * context information.
+     * @returns Decorated fields ready for creating a metrics event.
+     */
+    lint(eventFields, context = {}) {
+        const eventFieldsReader = new object_reader_1.ObjectReader(eventFields);
+        const eventType = eventFieldsReader.asString("eventType");
+        if (this.options.isLoggingEnabled) {
+            console.log(`Building event for event type: ${eventType !== null && eventType !== void 0 ? eventType : "<null>"}`);
+        }
+        // Make sure we have a deep copy of an object.
+        const decoratedEventFields = JSON.parse(JSON.stringify(eventFields));
+        const value = eventFieldsReader.asString("topic");
+        const topic = (0, optional_1.isSome)(value) ? (0, optional_1.unwrapOptional)(value) : this.options.defaultTopic;
+        this.decorateCommonEventFields(decoratedEventFields, topic);
+        switch (eventType) {
+            case "media" /* MetricsEventType.media */:
+                this.decorateMediaEventEvents(decoratedEventFields);
+                break;
+            default:
+                break;
+        }
+        for (const rule of this.options.rules) {
+            rule.apply(decoratedEventFields, context);
+        }
+        return {
+            fields: decoratedEventFields,
+        };
+    }
+}
+exports.EventLinter = EventLinter;
+//# sourceMappingURL=event-linter.js.map