refactor: Updated apollo server plugin to break out relevant functions into helpers

lib/common.js

@@ -0,0 +1,230 @@
+/*
+ * Copyright 2024 New Relic Corporation. All rights reserved.
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+'use strict'
+const ANON_PLACEHOLDER = '<anonymous>'
+const CATEGORY = 'GraphQL'
+const FRAMEWORK = 'ApolloServer'
+const OPERATION_PREFIX = CATEGORY + '/operation/' + FRAMEWORK
+const RESOLVE_PREFIX = CATEGORY + '/resolve/' + FRAMEWORK
+const ARG_PREFIX = `${CATEGORY}/arg/${FRAMEWORK}`
+const FIELD_PREFIX = `${CATEGORY}/field/${FRAMEWORK}`
+const BATCH_PREFIX = 'batch'
+const DEFAULT_OPERATION_NAME = `${OPERATION_PREFIX}/<unknown>`
+
+const FIELD_NAME_ATTR = 'graphql.field.name'
+const PARENT_TYPE_ATTR = 'graphql.field.parentType'
+const RETURN_TYPE_ATTR = 'graphql.field.returnType'
+const FIELD_PATH_ATTR = 'graphql.field.path'
+const OPERATION_TYPE_ATTR = 'graphql.operation.type'
+const OPERATION_NAME_ATTR = 'graphql.operation.name'
+const OPERATION_QUERY_ATTR = 'graphql.operation.query'
+const { getOperationDetails } = require('./utils')
+
+function setTransactionName(transaction, transactionName) {
+  const nameState = transaction.nameState
+  if (!nameState.graphql) {
+    // Override previously set path stack set thus far by web framework.
+    nameState.setName(nameState.prefix, nameState.verb, nameState.delimiter, transactionName)
+
+    // Indicate we've set a name via graphql and future attempts to name
+    // are a part of a batch query request to apollo.
+    nameState.graphql = true
+  } else {
+    // If this is a batch query, add 'batch' indicator to the first part of the
+    // name unless we've already done so processing a prior query in the batch.
+    const firstPart = nameState.pathStack[0]
+    if (firstPart.path !== BATCH_PREFIX) {
+      nameState.pathStack.unshift({ path: BATCH_PREFIX, params: null })
+    }
+
+    nameState.appendPath(transactionName)
+  }
+}
+
+function createOperationSegment(shim, parent) {
+  // We do not set to active here as batched queries will hit this
+  // back to back and we'd prefer those not nest with each-other.
+  return shim.createSegment(DEFAULT_OPERATION_NAME, recordOperationSegment, parent)
+}
+
+function createResolverSegment({ shim, parent, resolver, formattedPath }) {
+  // Nest everything under operation as resolvers start/finish
+  // in order but instrumentation such as promise tracking might
+  // try to treat as nested.
+  const resolverSegment = shim.createSegment(
+    `${RESOLVE_PREFIX}/${resolver.fieldName}`,
+    recordResolveSegment,
+    parent
+  )
+
+  if (!resolverSegment) {
+    return null
+  }
+
+  resolverSegment.start()
+  shim.setActiveSegment(resolverSegment)
+
+  resolverSegment.name = `${RESOLVE_PREFIX}/${formattedPath}`
+  resolverSegment.addAttribute(FIELD_PATH_ATTR, formattedPath)
+  resolverSegment.addAttribute(FIELD_NAME_ATTR, resolver.fieldName)
+  resolverSegment.addAttribute(RETURN_TYPE_ATTR, resolver.returnType.toString())
+  resolverSegment.addAttribute(PARENT_TYPE_ATTR, resolver.parentType.toString())
+  return resolverSegment
+}
+
+/**
+ * Creates metrics for resolver fields when transaction is ended.
+ * This will record how long specific resolvers took.
+ *
+ * @param {Object} params.config plugin config
+ * @param {Object} segment relevant resolver segment
+ * @param {string} scope name of transaction
+ */
+function recordResolveSegment(segment, scope) {
+  const duration = segment.getDurationInMillis()
+  const exclusive = segment.getExclusiveDurationInMillis()
+
+  const transaction = segment.transaction
+
+  const attributes = segment.getAttributes()
+  const fieldName = attributes[FIELD_NAME_ATTR]
+  const fieldType = attributes[PARENT_TYPE_ATTR]
+
+  // The segment name uses the path to differentiate between duplicate
+  // names resolving across different types. Here we use the field name
+  // with parent type to compare resolver across usage and transactions.
+  if (fieldName && fieldType) {
+    const typedFieldMetric = `${RESOLVE_PREFIX}/${fieldType}.${fieldName}`
+    createMetricPairs(transaction, typedFieldMetric, scope, duration, exclusive)
+  }
+}
+
+function recordOperationSegment(segment, scope) {
+  const duration = segment.getDurationInMillis()
+  const exclusive = segment.getExclusiveDurationInMillis()
+
+  const transaction = segment.transaction
+
+  createMetricPairs(transaction, segment.name, scope, duration, exclusive)
+}
+
+function createMetricPairs(transaction, name, scope, duration, exclusive) {
+  if (scope) {
+    transaction.measure(name, scope, duration, exclusive)
+  }
+
+  transaction.measure(name, null, duration, exclusive)
+}
+
+function createModuleUsageMetric(agent) {
+  agent.metrics
+    .getOrCreateMetric('Supportability/ExternalModules/ApolloServerPlugin')
+    .incrementCallCount()
+}
+
+/**
+ * Attempts to extract the document from the request context and
+ * add attributes for the query, operation type, operation name and
+ * update the transaction name based on operation name as well
+ *
+ * @param {Object} context apollo request context
+ * @param {Segment} operationSegment default segment created in request start
+ * @return {Boolean} true if document could be parsed from context
+ */
+function updateOperationSegmentName(context, operationSegment) {
+  const operationDetails = getOperationDetails(context)
+  if (operationDetails) {
+    const { operationName, operationType, deepestUniquePath, cleanedQuery } = operationDetails
+
+    operationSegment.addAttribute(OPERATION_QUERY_ATTR, cleanedQuery)
+
+    operationSegment.addAttribute(OPERATION_TYPE_ATTR, operationType)
+
+    if (operationName) {
+      operationSegment.addAttribute(OPERATION_NAME_ATTR, operationName)
+    }
+
+    const formattedName = operationName || ANON_PLACEHOLDER
+    let formattedOperation = `${operationType}/${formattedName}`
+
+    // Certain requests, such as introspection, won't hit any resolvers
+    if (deepestUniquePath) {
+      formattedOperation += `/${deepestUniquePath}`
+    }
+
+    const segmentName = formattedOperation
+    const transactionName = formattedOperation
+    setTransactionName(operationSegment.transaction, transactionName)
+    operationSegment.name = `${OPERATION_PREFIX}/${segmentName}`
+    return true
+  }
+
+  return false
+}
+
+/**
+ * Captures both field and args of resolvers as metrics.
+ *
+ * This is intended to be used to determine if a field within a graphql schema is still being requested.
+ *
+ * @param {Object} params
+ * @param {Object} params.config plugin config
+ * @param {Object} params.info info key from resolver context
+ * @param {Object} params.operationSegment operation segment
+ * @param {Object} params.args args key from resolver context
+ *
+ */
+function maybeCaptureFieldMetrics({ config, info, operationSegment, args }) {
+  if (config.captureFieldMetrics) {
+    const transaction = operationSegment.transaction
+    const fieldName = info.fieldName
+    const fieldType = info.parentType.toString()
+    captureFieldMetrics({ transaction, args, fieldName, fieldType })
+  }
+}
+
+/**
+ * Used to create metrics that just increment call count.  Intended to be
+ * used to report on when we see args in a resolver
+ *
+ * @param {Object} agent active agent instance
+ * @param {String} name metric name
+ */
+function createCallCountMetric(transaction, name) {
+  const metric = transaction.metrics.getOrCreateMetric(name)
+  metric.incrementCallCount()
+}
+
+/**
+ * Captures both field and args of resolvers as metrics.
+ *
+ * This is intended to be used to determine if a field within a graphql schema is still being requested.
+ *
+ * @param {Object} params
+ * @param {Object} params.transaction active transaction
+ * @param {Object} params.args args key from resolver context
+ * @param {Object} params.fieldType parent type of field
+ * @param {Object} params.fieldName name of field
+ *
+ */
+function captureFieldMetrics({ transaction, args, fieldType, fieldName }) {
+  const fieldMetric = `${FIELD_PREFIX}/${fieldType}.${fieldName}`
+  createCallCountMetric(transaction, fieldMetric)
+  Object.entries(args).forEach(([key]) => {
+    const name = `${ARG_PREFIX}/${fieldType}.${fieldName}/${key}`
+    createCallCountMetric(transaction, name)
+  })
+}
+
+module.exports = {
+  createModuleUsageMetric,
+  createOperationSegment,
+  createResolverSegment,
+  DEFAULT_OPERATION_NAME,
+  maybeCaptureFieldMetrics,
+  setTransactionName,
+  updateOperationSegmentName
+}