added ability to click on an error and open the offending file in VSCode

This adds the ability to quickly jump to the error in the source file on a failing test.
This fixes issue Raathigesh#186

server/api/app/resolver.ts

@@ -44,4 +44,22 @@ export default class AppResolver {
 
     return "";
   }
+
+  @Mutation(returns => String)
+  openFailure(@Arg("failure") failure: string) {
+    // The following regex matches the first line of the form: \w at <some text> (<file path>)
+    // it captures <file path> and returns that in the second position of the match array
+    let re = new RegExp('^\\s+at.*?\\((.*?)\\)$', 'm');
+    let match = failure.match(re);
+    if (match && match.length === 2) {
+      const path = match[1];
+      launch(path, process.env.EDITOR || "code", (path: string, err: any) => {
+        console.log("Failed to open file in editor. You may need to install the code command to your PATH if you are using VSCode: ", err);
+      });
+    }
+    else {
+      console.log("Failed to find a path to a file to load in the failure string.");
+    }
+    return "";
+  }
 }

ui/test-file/open-failure.gql

@@ -0,0 +1,3 @@
+mutation OpenFailure($failure: String!) {
+  openFailure(failure: $failure)
+}

ui/test-file/test-item.tsx

@@ -6,6 +6,8 @@ import TestIndicator from "./test-indicator";
 import { color, space } from "styled-system";
 import * as Convert from "ansi-to-html";
 import { CollapseStore } from "./collapseStore";
+import OPEN_FAILURE from "./open-failure.gql";
+import { useMutation } from "react-apollo-hooks";
 
 const convert = new Convert({
   colors: {
@@ -119,10 +121,19 @@ export default function Test({
     const newState = !hideChildren;
     setHideChildren(newState);
     CollapseStore.setState(id, newState);
+          if (children && children.length > 0) {
+    }
   }
+
+  const openFailure = useMutation(OPEN_FAILURE, {
+    variables: {
+      failure: testResult && testResult.failureMessages ? testResult.failureMessages[0] : ''
+    }
+  });
+
   return (
     <Container>
-      <Content only={only} onClick={() => toggleShowChildern()}>
+      <Content only={only} onClick={() => (children && children.length > 0) ? toggleShowChildern() : openFailure()}>
         <Label>
           { children && children.length > 0 && (
             <ViewToggle>