Merge pull request #1475 from probablyup/fix-mem-leak

fix streaming memory leak

CHANGELOG.md

@@ -6,6 +6,8 @@ All notable changes to this project will be documented in this file. If a contri
 
 ## Unreleased
 
+- Fix memory leak in the server-side streaming logic ([see #1475](https://github.com/styled-components/styled-components/pull/1475))
+
 ## [v3.1.4] - 2018-01-29
 
 - Disable "speedy" mode for IE and Edge. There seems to be some incompatibility with how the `insertRule` API functions in their rendering stack compared to the other vendors. (see [#1465](https://github.com/styled-components/styled-components/pull/1465)) _Note: this is currently being investigated for reimplementation._

src/models/ServerStyleSheet.js

@@ -153,19 +153,22 @@ export default class ServerStyleSheet {
     )
   }
 
+  close() {
+    clones.splice(clones.indexOf(this.instance), 1)
+    this.closed = true
+  }
+
   getStyleTags(): string {
     if (!this.closed) {
-      clones.splice(clones.indexOf(this.instance), 1)
-      this.closed = true
+      this.close()
     }
 
     return this.instance.toHTML()
   }
 
   getStyleElement() {
     if (!this.closed) {
-      clones.splice(clones.indexOf(this.instance), 1)
-      this.closed = true
+      this.close()
     }
 
     return this.instance.toReactElements()
@@ -193,12 +196,13 @@ export default class ServerStyleSheet {
       })
 
       readableStream.on('end', () => {
-        this.closed = true
         ourStream.push(null)
+        this.close()
       })
 
       readableStream.on('error', err => {
         ourStream.emit('error', err)
+        this.close()
       })
 
       return ourStream

src/test/ssr.test.js

@@ -239,6 +239,9 @@ describe('ssr', () => {
     `
 
     const sheet = new ServerStyleSheet()
+
+    jest.spyOn(sheet, 'close')
+
     const jsx = sheet.collectStyles(<Heading>Hello SSR!</Heading>)
     const stream = sheet.interleaveWithNodeStream(renderToNodeStream(jsx))
 
@@ -251,6 +254,7 @@ describe('ssr', () => {
 
       stream.on('end', () => {
         expect(received).toMatchSnapshot()
+        expect(sheet.close).toHaveBeenCalled()
         resolve()
       })