fix service name when tracer is imported by a dependency (#724)

.gitignore

@@ -110,4 +110,4 @@ versions
 build
 prebuilds
 docs/test.js
-!packages/*/test/node_modules
+!packages/*/test/**/node_modules

packages/dd-trace/src/platform/node/service.js

@@ -8,9 +8,25 @@ function service () {
   const callerPath = parentModule()
   const parentPath = parentModule(callerPath)
   const cwd = path.dirname(parentPath || callerPath)
-  const pkg = readPkgUp.sync({ cwd }).pkg || {}
+  const pkg = findPkg(cwd)
 
   return pkg.name
 }
 
+function findPkg (cwd) {
+  let up = readPkgUp.sync({ cwd })
+
+  while (up && isDependency(up.path)) {
+    cwd = path.resolve(path.dirname(up.path), '..')
+    up = readPkgUp.sync({ cwd })
+  }
+
+  return up && up.pkg ? up.pkg : {}
+}
+
+function isDependency (filepath) {
+  const expr = new RegExp(`\\${path.sep}node_modules\\${path.sep}`)
+  return expr.test(filepath)
+}
+
 module.exports = service

packages/dd-trace/test/platform/node/index.spec.js

@@ -206,6 +206,12 @@ describe('Platform', () => {
 
         expect(name).to.equal('foo')
       })
+
+      it('should work even in dependencies', () => {
+        const name = require('./load/node_modules/dep')
+
+        expect(name).to.equal('foo')
+      })
     })
 
     describe('request', () => {