1 files changed, 75 insertions, 31 deletions

diff --git a/packages/dev-tools-pages/ts/components/Code.tsx b/packages/dev-tools-pages/ts/components/Code.tsx
index 5a03e79ac..ce4443357 100644
--- a/packages/dev-tools-pages/ts/components/Code.tsx
+++ b/packages/dev-tools-pages/ts/components/Code.tsx
@@ -4,12 +4,13 @@ import styled from 'styled-components';
 import { colors } from 'ts/variables';
 import BaseButton from './Button';
 
-var highlight = require('highlighter')();
-
 interface CodeProps {
     children: React.ReactNode;
     language?: string;
     light?: boolean;
+    diff?: boolean;
+    gutter?: Array<number>;
+    gutterLength?: number;
 }
 
 interface CodeState {
@@ -30,37 +31,73 @@ const Button = styled(BaseButton)`
 
 const Base =
     styled.div <
-        CodeProps >
-        `
+    CodeProps >
+    `
     color: ${props => (props.language === undefined ? colors.white : 'inherit')};
     background-color: ${props =>
-            props.light ? 'rgba(255,255,255,.15)' : props.language === undefined ? colors.black : colors.lightGray};
+        props.light ? 'rgba(255,255,255,.15)' : props.language === undefined ? colors.black : '#F1F4F5'};
     white-space: ${props => (props.language === undefined ? 'nowrap' : '')};
     position: relative;
+
+    ${props =>
+        props.diff
+            ? `
+        background-color: #E9ECED;
+        display: flex;
+        padding-top: 1.5rem;
+        padding-bottom: 1.5rem;
+    `
+            : `
+        padding: 1.5rem;
+    `}
+
+    overflow-y: scroll;
+    -webkit-overflow-scrolling: touch;
+
     &:hover ${Button} {
         opacity: 1;
     }
 `;
 
-const StyledCode = styled.code`
-    padding-top: 1.5rem;
-    padding-bottom: 1.5rem;
-    display: block;
-    overflow-y: scroll;
-    -webkit-overflow-scrolling: touch;
+const StyledCodeDiff =
+    styled.code <
+    any >
+    `
+    ::before {
+        content: '';
+        width: calc(.75rem + ${props => props.gutterLength}ch);
+        background-color: #e2e5e6;
+        position: absolute;
+        top: 0;
+        left: 0;
+        bottom: 0;
+    }
 
-    
-    .diff-addition {
-        background-color: #d2e9e0;
-        padding: 0.3125rem;
+    [class^='line-'] {
         display: inline-block;
         width: 100%;
+        position: relative;
+        padding-right: 1.5rem;
+        padding-left: calc(2.25rem + ${props => props.gutterLength}ch);
+        ::before {
+            content: attr(data-test);
+            font-size: 0.875rem;
+            width: ${props => props.gutterLength};
+            padding-left: .375rem;
+            padding-right: .375rem;
+            position: absolute;
+            top: 50%;
+            left: 0;
+            transform: translateY(-50%);
+            z-index: 1;
+        }
     }
-    .diff-deletion {
-        background-color: #ebdcdc;
-        padding: 0.3125rem;
-        display: inline-block;
-        width: 100%;
+
+    .line-addition {
+        background-color: rgba(0, 202, 105, 0.1);
+    }
+    .line-deletion {
+        background-color: rgba(255, 0, 0, 0.07);
     }
 `;
 
@@ -88,13 +125,16 @@ class Code extends React.Component<CodeProps, CodeState> {
     }
 
     async componentDidMount() {
-        const { language, children } = this.props;
+        const { language, children, diff, gutter } = this.props;
+
+        const code = children as string;
 
         if (language !== undefined) {
-            const { default: hljs } = await System.import(/* webpackChunkName: 'highlightjs' */ 'ts/highlight');
+            const { default: highlight } = await System.import(/* webpackChunkName: 'highlightjs' */ 'ts/highlight');
 
-            const hlCode = hljs(children as string, language);
-            this.setState({ hlCode });
+            this.setState({
+                hlCode: highlight(language, code, diff, gutter),
+            });
         }
     }
 
@@ -115,16 +155,20 @@ class Code extends React.Component<CodeProps, CodeState> {
     };
 
     render() {
-        const { language, light, children } = this.props;
+        const { language, light, diff, children, gutterLength } = this.props;
+        const { hlCode } = this.state;
+
+        const Code = diff ? StyledCodeDiff : 'code';
 
         return (
-            <Base language={language} light={light}>
+            <Base language={language} diff={diff} light={light}>
                 <StyledPre>
-                    {this.state.hlCode !== undefined ? (
-                        <StyledCode dangerouslySetInnerHTML={{ __html: this.state.hlCode }} />
-                    ) : (
-                            <StyledCode>{this.props.children}</StyledCode>
-                        )}
+                    <Code
+                        gutterLength={gutterLength}
+                        dangerouslySetInnerHTML={hlCode ? { __html: this.state.hlCode } : null}
+                    >
+                        {hlCode === undefined ? children : null}
+                    </Code>
                 </StyledPre>
                 {navigator.userAgent !== 'ReactSnap' ? <Button onClick={this.handleCopy}>Copy</Button> : null}
                 {!('clipboard' in navigator) ? (