[Backport 7.x] Allow the client name to be a symbol (#1257)

Co-authored-by: Tomas Della Vedova <delvedor@users.noreply.github.com>

docs/configuration.asciidoc

@@ -178,7 +178,7 @@ function generateRequestId (params, options) {
 ----
 
 |`name`
-|`string` - The name to identify the client instance in the events. +
+|`string | symbol` - The name to identify the client instance in the events. +
 _Default:_ `elasticsearch-js`
 
 |`opaqueIdPrefix`

index.d.ts

@@ -88,7 +88,7 @@ interface ClientOptions {
   headers?: Record<string, any>;
   opaqueIdPrefix?: string;
   generateRequestId?: generateRequestIdFn;
-  name?: string;
+  name?: string | symbol;
   auth?: BasicAuth | ApiKeyAuth;
   cloud?: {
     id: string;

lib/Transport.d.ts

@@ -52,7 +52,7 @@ export interface RequestEvent<TResponse = Record<string, any>, TContext = unknow
   warnings: string[] | null;
   meta: {
     context: TContext;
-    name: string;
+    name: string | symbol;
     request: {
       params: TransportRequestParams;
       options: TransportRequestOptions;

test/acceptance/observability.test.js

@@ -205,7 +205,7 @@ test('Client name', t => {
     t.end()
   })
 
-  t.test('Is present in the event metadata', t => {
+  t.test('Is present in the event metadata (as string)', t => {
     t.plan(6)
     const client = new Client({
       node: 'http://localhost:9200',
@@ -229,6 +229,31 @@ test('Client name', t => {
     })
   })
 
+  t.test('Is present in the event metadata (as symbol)', t => {
+    t.plan(6)
+    const symbol = Symbol('cluster')
+    const client = new Client({
+      node: 'http://localhost:9200',
+      Connection: MockConnection,
+      name: symbol
+    })
+
+    client.on('request', (err, { meta }) => {
+      t.error(err)
+      t.strictEqual(meta.name, symbol)
+    })
+
+    client.on('response', (err, { meta }) => {
+      t.error(err)
+      t.strictEqual(meta.name, symbol)
+    })
+
+    client.info((err, { meta }) => {
+      t.error(err)
+      t.strictEqual(meta.name, symbol)
+    })
+  })
+
   t.test('Sniff and client name', t => {
     t.test('sniffOnStart', t => {
       t.plan(2)

test/types/client-options.test-d.ts

@@ -300,6 +300,13 @@ expectType<Client>(
   })
 )
 
+expectType<Client>(
+  new Client({
+    node: 'http://localhost:9200',
+    name: Symbol('foo')
+  })
+)
+
 expectError<errors.ConfigurationError>(
   new Client({
     node: 'http://localhost:9200',

test/unit/client.test.js

@@ -1092,3 +1092,26 @@ test('Random selector', t => {
     })
   })
 })
+
+test('name property as string', t => {
+  t.plan(1)
+
+  const client = new Client({
+    node: 'http://localhost:9200',
+    name: 'client-name'
+  })
+
+  t.strictEqual(client.name, 'client-name')
+})
+
+test('name property as symbol', t => {
+  t.plan(1)
+
+  const symbol = Symbol('client-name')
+  const client = new Client({
+    node: 'http://localhost:9200',
+    name: symbol
+  })
+
+  t.strictEqual(client.name, symbol)
+})