fix: GraphQL throws TypeError: Cannot read property 'startToken' of u…

…ndefined (#619)

Co-authored-by: Daniel Dyla <dyladan@users.noreply.github.com>

examples/graphql/README.md

@@ -46,6 +46,12 @@ npm install
     ```
 
 5. You can also write your own queries, open page `http://localhost:4000/graphql`
+6. You can also test a `graphql-transform-federation`
+    ```shell script
+    # from this directory
+    npm run server:federation
+    npm run client:federation
+    ```
 
 ## Useful links
 

examples/graphql/client-federation.js

@@ -0,0 +1,44 @@
+'use strict';
+
+const url = require('url');
+const http = require('http');
+// Construct a schema, using GraphQL schema language
+
+const source = `
+{
+  continents {
+    code
+    name
+  }
+}
+`;
+
+makeRequest(source).then(console.log);
+
+function makeRequest(query) {
+  return new Promise((resolve, reject) => {
+    const parsedUrl = new url.URL('http://localhost:4000/graphql');
+    const options = {
+      hostname: parsedUrl.hostname,
+      port: parsedUrl.port,
+      path: parsedUrl.pathname,
+      method: 'POST',
+      headers: {
+        'Content-Type': 'application/json',
+      },
+    };
+    const req = http.request(options, (res) => {
+      const data = [];
+      res.on('data', (chunk) => data.push(chunk));
+      res.on('end', () => {
+        resolve(data.toString());
+      });
+      res.on('error', (err) => {
+        reject(err);
+      });
+    });
+
+    req.write(JSON.stringify({ query }));
+    req.end();
+  });
+}

examples/graphql/countries-service.js

@@ -0,0 +1,31 @@
+'use strict';
+
+const { fetch } = require('cross-fetch');
+const { print } = require('graphql');
+const { wrapSchema, introspectSchema } = require('@graphql-tools/wrap');
+const { transformSchemaFederation } = require('graphql-transform-federation');
+
+const executor = async ({ document, variables }) => {
+  const query = print(document);
+  const fetchResult = await fetch('https://countries.trevorblades.com/', {
+    method: 'POST',
+    headers: {
+      'Content-Type': 'application/json',
+    },
+    body: JSON.stringify({ query, variables }),
+  });
+  return fetchResult.json();
+};
+
+module.exports = async () => {
+  const schema = wrapSchema({
+    schema: await introspectSchema(executor),
+    executor,
+  });
+
+  return transformSchemaFederation(schema, {
+    Query: {
+      extend: true,
+    },
+  });
+};

examples/graphql/package.json

@@ -6,11 +6,13 @@
   "main": "index.js",
   "scripts": {
     "client": "node ./client.js",
+    "client:federation": "node ./client-federation.js",
     "docker:start": "cd ./docker && docker-compose down && docker-compose up",
     "docker:startd": "cd ./docker && docker-compose down && docker-compose up -d",
     "docker:stop": "cd ./docker && docker-compose down",
+    "server:apollo": "node ./server-apollo.js",
     "server:express": "node ./server-express.js",
-    "server:apollo": "node ./server-apollo.js"
+    "server:federation": "node ./server-federation.js"
   },
   "repository": {
     "type": "git",
@@ -31,18 +33,22 @@
     "url": "https://github.com/open-telemetry/opentelemetry-js/issues"
   },
   "dependencies": {
+    "@apollo/gateway": "^0.19.1",
+    "@graphql-tools/wrap": "^6.0.18",
     "@opentelemetry/api": "^1.0.2",
     "@opentelemetry/exporter-collector": "^0.25.0",
     "@opentelemetry/instrumentation": "^0.25.0",
-    "@opentelemetry/instrumentation-express": "^0.23.0",
-    "@opentelemetry/instrumentation-graphql": "^0.23.0",
+    "@opentelemetry/instrumentation-express": "^0.24.0",
+    "@opentelemetry/instrumentation-graphql": "^0.24.0",
     "@opentelemetry/instrumentation-http": "^0.25.0",
-    "@opentelemetry/sdk-trace-node": "^0.25.0",
-    "@opentelemetry/sdk-trace-base": "^0.25.0",
+    "@opentelemetry/node": "^0.25.0",
+    "@opentelemetry/tracing": "^0.25.0",
     "apollo-server": "^2.18.1",
+    "cross-fetch": "^3.0.5",
     "express": "^4.17.1",
     "express-graphql": "^0.11.0",
-    "graphql": "^15.3.0"
+    "graphql": "^15.3.0",
+    "graphql-transform-federation": "^2.1.0"
   },
   "homepage": "https://github.com/open-telemetry/opentelemetry-js#readme",
   "devDependencies": {

examples/graphql/server-federation.js

@@ -0,0 +1,54 @@
+'use strict';
+
+require('./tracer');
+
+const { ApolloServer } = require('apollo-server');
+const {
+  ApolloGateway,
+  RemoteGraphQLDataSource,
+  LocalGraphQLDataSource,
+} = require('@apollo/gateway');
+
+const getCountriesSchema = require('./countries-service');
+
+const setupGateway = async () => {
+  const countriesSchema = await getCountriesSchema();
+
+  const gateway = new ApolloGateway({
+    serviceList: [{ name: 'countries', url: 'http://countries' }],
+
+    // Experimental: Enabling this enables the query plan view in Playground.
+    __exposeQueryPlanExperimental: false,
+
+    buildService: ({ url }) => {
+      if (url === 'http://countries') {
+        return new LocalGraphQLDataSource(countriesSchema);
+      }
+      return new RemoteGraphQLDataSource({
+        url,
+      });
+    },
+  });
+
+  return gateway;
+};
+
+(async () => {
+  const gateway = await setupGateway();
+
+  const server = new ApolloServer({
+    gateway,
+
+    // Apollo Graph Manager (previously known as Apollo Engine)
+    // When enabled and an `ENGINE_API_KEY` is set in the environment,
+    // provides metrics, schema management and trace reporting.
+    engine: false,
+
+    // Subscriptions are unsupported but planned for a future Gateway version.
+    subscriptions: false,
+  });
+
+  server.listen().then(({ url }) => {
+    console.log(`🚀 Server ready at ${url}`);
+  });
+})();

package.json

@@ -30,7 +30,8 @@
     "lint": "lerna run lint",
     "lint:fix": "lerna run lint:fix",
     "lint:examples": "eslint ./examples/**/*.js",
-    "lint:examples:fix": "eslint ./examples/**/*.js --fix"
+    "lint:examples:fix": "eslint ./examples/**/*.js --fix",
+    "lerna:scope": "lerna bootstrap --include-dependents --include-dependencies --scope"
   },
   "keywords": [
     "opentelemetry",

plugins/node/opentelemetry-instrumentation-graphql/src/utils.ts

@@ -34,7 +34,7 @@ const OPERATION_VALUES = Object.values(AllowedOperationTypes);
 
 export function addSpanSource(
   span: api.Span,
-  loc: graphqlTypes.Location,
+  loc?: graphqlTypes.Location,
   allowValues?: boolean,
   start?: number,
   end?: number
@@ -212,14 +212,17 @@ const KindsToBeRemoved: string[] = [
 ];
 
 export function getSourceFromLocation(
-  loc: graphqlTypes.Location,
+  loc?: graphqlTypes.Location,
   allowValues = false,
-  start: number = loc.start,
-  end: number = loc.end
+  inputStart?: number,
+  inputEnd?: number
 ): string {
   let source = '';
 
-  if (loc.startToken) {
+  if (loc?.startToken) {
+    const start = typeof inputStart === 'number' ? inputStart : loc.start;
+    const end = typeof inputEnd === 'number' ? inputEnd : loc.end;
+
     let next: graphqlTypes.Token | null = loc.startToken.next;
     let previousLine: number | undefined = 1;
     while (next) {