From f59c226bfe53d08b7b7bbea6715cf94c2b668812 Mon Sep 17 00:00:00 2001
From: Riley Bauer <34456002+rileyjbauer@users.noreply.github.com>
Date: Mon, 26 Nov 2018 12:09:39 -0800
Subject: [PATCH] Disables back button when there is no history (#377)

This can happen whenever a user opens up a page from a URL.

A common way to hit this is to create a run from a notebook and click the link to see it in the UI.
---
 frontend/server/package-lock.json             |   6 +-
 frontend/src/components/Toolbar.test.tsx      |  14 +-
 frontend/src/components/Toolbar.tsx           |  20 +-
 .../__snapshots__/Toolbar.test.tsx.snap       | 239 ++++++++++++++----
 4 files changed, 221 insertions(+), 58 deletions(-)

diff --git a/frontend/server/package-lock.json b/frontend/server/package-lock.json
index a1f113c9ab9..2e0e25e2577 100644
--- a/frontend/server/package-lock.json
+++ b/frontend/server/package-lock.json
@@ -229,7 +229,7 @@
     },
     "@types/websocket": {
       "version": "0.0.38",
-      "resolved": "https://registry.npmjs.org/@types/websocket/-/websocket-0.0.38.tgz",
+      "resolved": "http://registry.npmjs.org/@types/websocket/-/websocket-0.0.38.tgz",
       "integrity": "sha512-Z7dRTAiMoIjz9HBa/xb3k+2mx2uJx2sbnbkRRIvM+l/srNLfthHFBW/jD59thOcEa1/ZooKd30G0D+KGH9wU7Q==",
       "requires": {
         "@types/events": "*",
@@ -601,7 +601,7 @@
     },
     "colors": {
       "version": "0.5.1",
-      "resolved": "https://registry.npmjs.org/colors/-/colors-0.5.1.tgz",
+      "resolved": "http://registry.npmjs.org/colors/-/colors-0.5.1.tgz",
       "integrity": "sha1-fQAj6usVTo7p/Oddy5I9DtFmd3Q="
     },
     "combined-stream": {
@@ -2107,7 +2107,7 @@
     },
     "path-is-absolute": {
       "version": "1.0.1",
-      "resolved": "https://registry.npmjs.org/path-is-absolute/-/path-is-absolute-1.0.1.tgz",
+      "resolved": "http://registry.npmjs.org/path-is-absolute/-/path-is-absolute-1.0.1.tgz",
       "integrity": "sha1-F0uSaHNVNP+8es5r9TpanhtcX18="
     },
     "path-parse": {
diff --git a/frontend/src/components/Toolbar.test.tsx b/frontend/src/components/Toolbar.test.tsx
index 55131ab6d9b..db270da4b5b 100644
--- a/frontend/src/components/Toolbar.test.tsx
+++ b/frontend/src/components/Toolbar.test.tsx
@@ -16,7 +16,7 @@
 
 import * as React from 'react';
 import { shallow } from 'enzyme';
-import { createBrowserHistory } from 'history';
+import { createBrowserHistory, createMemoryHistory } from 'history';
 import Toolbar from './Toolbar';
 import HelpIcon from '@material-ui/icons/Help';
 import InfoIcon from '@material-ui/icons/Info';
@@ -57,6 +57,10 @@ const breadcrumbs = [
 const history = createBrowserHistory({});
 
 describe('Toolbar', () => {
+  beforeAll(() => {
+    history.push('/pipelines');
+  });
+
   it('renders nothing when there are no breadcrumbs or actions', () => {
     const tree = shallow(<Toolbar breadcrumbs={[]} actions={[]} history={history} pageTitle='' />);
     expect(tree).toMatchSnapshot();
@@ -154,4 +158,12 @@ describe('Toolbar', () => {
       history={history} />);
     expect(tree).toMatchSnapshot();
   });
+
+  it('disables the back button when there is no browser history', () => {
+    // This test uses createMemoryHistory because createBroweserHistory returns a singleton, and
+    // there is no way to clear its entries which this test requires.
+    const emptyHistory = createMemoryHistory();
+    const tree = shallow(<Toolbar breadcrumbs={breadcrumbs} actions={actions} history={emptyHistory} pageTitle='' />);
+    expect(tree).toMatchSnapshot();
+  });
 });
diff --git a/frontend/src/components/Toolbar.tsx b/frontend/src/components/Toolbar.tsx
index 874976da141..903085b8355 100644
--- a/frontend/src/components/Toolbar.tsx
+++ b/frontend/src/components/Toolbar.tsx
@@ -51,7 +51,6 @@ const css = stylesheet({
     marginRight: spacing.units(-2),
   },
   backIcon: {
-    color: color.foreground,
     fontSize: backIconHeight,
     verticalAlign: 'bottom',
   },
@@ -70,6 +69,12 @@ const css = stylesheet({
   chevron: {
     height: 12,
   },
+  disabled: {
+    color: '#aaa',
+  },
+  enabled: {
+    color: color.foreground,
+  },
   link: {
     $nest: {
       '&:hover': {
@@ -136,11 +141,14 @@ class Toolbar extends React.Component<ToolbarProps> {
             {/* Back Arrow */}
             {breadcrumbs.length > 0 &&
               <Tooltip title={'Back'} enterDelay={300}>
-                <IconButton className={css.backLink}
-                  // Need to handle this for when browsing back doesn't make sense
-                  onClick={this.props.history!.goBack}>
-                  <ArrowBackIcon className={css.backIcon} />
-                </IconButton>
+                <div> {/* Div needed because we sometimes disable a button within a tooltip */}
+                  <IconButton className={css.backLink}
+                    disabled={this.props.history!.length < 2}
+                    onClick={this.props.history!.goBack}>
+                    <ArrowBackIcon className={
+                      classes(css.backIcon, this.props.history!.length < 2 ? css.disabled : css.enabled)} />
+                  </IconButton>
+                </div>
               </Tooltip>}
             {/* Resource Name */}
             <span className={classes(css.pageName, commonCss.ellipsis)} title={pageTitleTooltip}>
diff --git a/frontend/src/components/__snapshots__/Toolbar.test.tsx.snap b/frontend/src/components/__snapshots__/Toolbar.test.tsx.snap
index 1bfd6084169..fa72b643e00 100644
--- a/frontend/src/components/__snapshots__/Toolbar.test.tsx.snap
+++ b/frontend/src/components/__snapshots__/Toolbar.test.tsx.snap
@@ -1,5 +1,124 @@
 // Jest Snapshot v1, https://goo.gl/fbAQLP
 
+exports[`Toolbar disables the back button when there is no browser history 1`] = `
+<div
+  className="root topLevelToolbar"
+>
+  <div
+    style={
+      Object {
+        "minWidth": 100,
+      }
+    }
+  >
+    <div
+      className="breadcrumbs flex"
+    >
+      <span
+        className="flex"
+        key="0"
+        title="test display name"
+      >
+        <Link
+          className="unstyled ellipsis link"
+          replace={false}
+          to="/some/test/path"
+        >
+          test display name
+        </Link>
+      </span>
+      <span
+        className="flex"
+        key="1"
+        title="test display name2"
+      >
+        <pure(ChevronRightIcon)
+          className="chevron"
+        />
+        <Link
+          className="unstyled ellipsis link"
+          replace={false}
+          to="/some/test/path2"
+        >
+          test display name2
+        </Link>
+      </span>
+    </div>
+    <div
+      className="flex"
+    >
+      <WithStyles(Tooltip)
+        enterDelay={300}
+        title="Back"
+      >
+        <div>
+           
+          <WithStyles(IconButton)
+            className="backLink"
+            disabled={true}
+            onClick={[Function]}
+          >
+            <pure(ArrowBackIcon)
+              className="backIcon disabled"
+            />
+          </WithStyles(IconButton)>
+        </div>
+      </WithStyles(Tooltip)>
+      <span
+        className="pageName ellipsis"
+      />
+    </div>
+  </div>
+  <div
+    className="actions"
+  >
+    <WithStyles(Tooltip)
+      enterDelay={300}
+      key="0"
+      title="test tooltip"
+    >
+      <div>
+        <BusyButton
+          busy={false}
+          className=""
+          color="secondary"
+          icon={[Function]}
+          id="test id"
+          onClick={
+            [MockFunction] {
+              "calls": Array [
+                Array [],
+              ],
+            }
+          }
+          outlined={false}
+          title="test title"
+        />
+      </div>
+    </WithStyles(Tooltip)>
+    <WithStyles(Tooltip)
+      enterDelay={300}
+      key="1"
+      title="test disabled title2"
+    >
+      <div>
+        <BusyButton
+          busy={false}
+          className=""
+          color="secondary"
+          disabled={true}
+          icon={[Function]}
+          id="test id2"
+          onClick={[MockFunction]}
+          outlined={false}
+          title="test title2"
+        />
+      </div>
+    </WithStyles(Tooltip)>
+  </div>
+</div>
+`;
+
 exports[`Toolbar renders nothing when there are no breadcrumbs or actions 1`] = `""`;
 
 exports[`Toolbar renders outlined action buttons 1`] = `
@@ -53,14 +172,18 @@ exports[`Toolbar renders outlined action buttons 1`] = `
         enterDelay={300}
         title="Back"
       >
-        <WithStyles(IconButton)
-          className="backLink"
-          onClick={[Function]}
-        >
-          <pure(ArrowBackIcon)
-            className="backIcon"
-          />
-        </WithStyles(IconButton)>
+        <div>
+           
+          <WithStyles(IconButton)
+            className="backLink"
+            disabled={false}
+            onClick={[Function]}
+          >
+            <pure(ArrowBackIcon)
+              className="backIcon enabled"
+            />
+          </WithStyles(IconButton)>
+        </div>
       </WithStyles(Tooltip)>
       <span
         className="pageName ellipsis"
@@ -142,14 +265,18 @@ exports[`Toolbar renders primary action buttons 1`] = `
         enterDelay={300}
         title="Back"
       >
-        <WithStyles(IconButton)
-          className="backLink"
-          onClick={[Function]}
-        >
-          <pure(ArrowBackIcon)
-            className="backIcon"
-          />
-        </WithStyles(IconButton)>
+        <div>
+           
+          <WithStyles(IconButton)
+            className="backLink"
+            disabled={false}
+            onClick={[Function]}
+          >
+            <pure(ArrowBackIcon)
+              className="backIcon enabled"
+            />
+          </WithStyles(IconButton)>
+        </div>
       </WithStyles(Tooltip)>
       <span
         className="pageName ellipsis"
@@ -231,14 +358,18 @@ exports[`Toolbar renders primary action buttons without outline, even if outline
         enterDelay={300}
         title="Back"
       >
-        <WithStyles(IconButton)
-          className="backLink"
-          onClick={[Function]}
-        >
-          <pure(ArrowBackIcon)
-            className="backIcon"
-          />
-        </WithStyles(IconButton)>
+        <div>
+           
+          <WithStyles(IconButton)
+            className="backLink"
+            disabled={false}
+            onClick={[Function]}
+          >
+            <pure(ArrowBackIcon)
+              className="backIcon enabled"
+            />
+          </WithStyles(IconButton)>
+        </div>
       </WithStyles(Tooltip)>
       <span
         className="pageName ellipsis"
@@ -320,14 +451,18 @@ exports[`Toolbar renders with two breadcrumbs and two actions 1`] = `
         enterDelay={300}
         title="Back"
       >
-        <WithStyles(IconButton)
-          className="backLink"
-          onClick={[Function]}
-        >
-          <pure(ArrowBackIcon)
-            className="backIcon"
-          />
-        </WithStyles(IconButton)>
+        <div>
+           
+          <WithStyles(IconButton)
+            className="backLink"
+            disabled={false}
+            onClick={[Function]}
+          >
+            <pure(ArrowBackIcon)
+              className="backIcon enabled"
+            />
+          </WithStyles(IconButton)>
+        </div>
       </WithStyles(Tooltip)>
       <span
         className="pageName ellipsis"
@@ -419,14 +554,18 @@ exports[`Toolbar renders without actions and one breadcrumb 1`] = `
         enterDelay={300}
         title="Back"
       >
-        <WithStyles(IconButton)
-          className="backLink"
-          onClick={[Function]}
-        >
-          <pure(ArrowBackIcon)
-            className="backIcon"
-          />
-        </WithStyles(IconButton)>
+        <div>
+           
+          <WithStyles(IconButton)
+            className="backLink"
+            disabled={false}
+            onClick={[Function]}
+          >
+            <pure(ArrowBackIcon)
+              className="backIcon enabled"
+            />
+          </WithStyles(IconButton)>
+        </div>
       </WithStyles(Tooltip)>
       <span
         className="pageName ellipsis"
@@ -474,14 +613,18 @@ exports[`Toolbar renders without actions, one breadcrumb, and a page name 1`] =
         enterDelay={300}
         title="Back"
       >
-        <WithStyles(IconButton)
-          className="backLink"
-          onClick={[Function]}
-        >
-          <pure(ArrowBackIcon)
-            className="backIcon"
-          />
-        </WithStyles(IconButton)>
+        <div>
+           
+          <WithStyles(IconButton)
+            className="backLink"
+            disabled={false}
+            onClick={[Function]}
+          >
+            <pure(ArrowBackIcon)
+              className="backIcon enabled"
+            />
+          </WithStyles(IconButton)>
+        </div>
       </WithStyles(Tooltip)>
       <span
         className="pageName ellipsis"