From 4e360a921011b003153c5d7568abf8f4259bdecd Mon Sep 17 00:00:00 2001
From: Nick Mitchell <nickm@us.ibm.com>
Date: Fri, 4 Jun 2021 13:16:02 -0400
Subject: [PATCH] fix(plugins/plugin-client-common): when rerunning blocks,
 output always scrolls to bottom

part of #7527
---
 .../src/components/Views/Terminal/Block/BlockModel.ts |  4 ++++
 .../src/components/Views/Terminal/Block/Output.tsx    |  4 +++-
 .../components/Views/Terminal/ScrollableTerminal.tsx  | 11 ++++++++++-
 3 files changed, 17 insertions(+), 2 deletions(-)

diff --git a/plugins/plugin-client-common/src/components/Views/Terminal/Block/BlockModel.ts b/plugins/plugin-client-common/src/components/Views/Terminal/Block/BlockModel.ts
index ec80fb64ea8..c106ed0b4f6 100644
--- a/plugins/plugin-client-common/src/components/Views/Terminal/Block/BlockModel.ts
+++ b/plugins/plugin-client-common/src/components/Views/Terminal/Block/BlockModel.ts
@@ -204,6 +204,10 @@ export function hasOriginalUUID(block: BlockModel | WithOriginalExecUUID): block
   return typeof (block as WithOriginalExecUUID).originalExecUUID === 'string'
 }
 
+export function hasBeenRerun(block: BlockModel): boolean {
+  return hasOriginalUUID(block)
+}
+
 /** Transform to Processing */
 export function Processing(
   block: BlockModel,
diff --git a/plugins/plugin-client-common/src/components/Views/Terminal/Block/Output.tsx b/plugins/plugin-client-common/src/components/Views/Terminal/Block/Output.tsx
index 4ed92c8860b..fef02060949 100644
--- a/plugins/plugin-client-common/src/components/Views/Terminal/Block/Output.tsx
+++ b/plugins/plugin-client-common/src/components/Views/Terminal/Block/Output.tsx
@@ -45,6 +45,7 @@ import {
   FinishedBlock,
   hasUUID,
   hasCommand,
+  hasBeenRerun,
   isBeingRerun,
   isFinished,
   isProcessing,
@@ -171,7 +172,8 @@ export default class Output extends React.PureComponent<Props, State> {
   }
 
   private onRender(assertHasContent: boolean): void {
-    if (this.props.onRender) {
+    if (this.props.onRender && !this.props.isBeingRerun && !hasBeenRerun(this.props.model)) {
+      // we don't want reruns to trigger any scrolling behavior
       this.props.onRender()
     }
     this.setState({ assertHasContent })
diff --git a/plugins/plugin-client-common/src/components/Views/Terminal/ScrollableTerminal.tsx b/plugins/plugin-client-common/src/components/Views/Terminal/ScrollableTerminal.tsx
index 33667091ca8..7c39772ac42 100644
--- a/plugins/plugin-client-common/src/components/Views/Terminal/ScrollableTerminal.tsx
+++ b/plugins/plugin-client-common/src/components/Views/Terminal/ScrollableTerminal.tsx
@@ -143,6 +143,7 @@ type ScrollbackState = ScrollbackOptions & {
   onFocus: (evt: React.FocusEvent) => void
   onOutputRender: () => void
   navigateTo: (dir: 'first' | 'last' | 'previous' | 'next') => void
+  setActiveBlock: (c: Block) => void
   willFocusBlock: (evt: React.SyntheticEvent) => void
   willRemoveBlock: (evt: React.SyntheticEvent, idx?: number) => void
   willUpdateCommand: (idx: number, command: string) => void
@@ -403,6 +404,7 @@ export default class ScrollableTerminal extends React.PureComponent<Props, State
       onFocus: undefined,
       onOutputRender: undefined,
       navigateTo: undefined,
+      setActiveBlock: undefined,
       willFocusBlock: undefined,
       willRemoveBlock: undefined,
       willUpdateCommand: undefined
@@ -462,6 +464,13 @@ export default class ScrollableTerminal extends React.PureComponent<Props, State
       })
     }
 
+    /** Update the active block */
+    state.setActiveBlock = (c: Block) => {
+      if (c && c.props && c.props.model && isActive(c.props.model)) {
+        state._activeBlock = c
+      }
+    }
+
     /**
      * User clicked to focus a block.
      *
@@ -1327,7 +1336,7 @@ export default class ScrollableTerminal extends React.PureComponent<Props, State
                     isWidthConstrained={isWidthConstrained}
                     onOutputRender={scrollback.onOutputRender}
                     navigateTo={scrollback.navigateTo}
-                    ref={idx !== this.findActiveBlock(scrollback) ? undefined : c => (scrollback._activeBlock = c)}
+                    ref={scrollback.setActiveBlock}
                   />
                 )
               })