Merge #11200

11200: [cli] Reimplement the interactive renderer r=pgavlin a=pgavlin

The display pipleline looks like this:

```
       ╭──────╮
       │Engine│
       ╰──────╯
          ⬇ engine events
   ╭────────────────╮
   │Progress Display│
   ╰────────────────╯
          ⬇ display events: ticks, resource updates, system messages
   ╭─────────────────╮
   │Progress Renderer│
   ╰─────────────────╯
          ⬇ text
      ╭────────╮
      │Terminal│
      ╰────────╯
```

The existing implementation of the interactive Progress Renderer is broken
into two parts, the display renderer and the message renderer. The display
renderer converts display events into progress messages, each of which
generally represents a single line of text at a particular position in
the output. The message renderer converts progress messages into screen
updates by identifying whether or not the contents of a particular
message have changed and if so, re-rendering its output line. In
somewhat greater detail:

```
   ╭────────────────╮
   │Display Renderer│
   ╰────────────────╯
          ⬇ convert resource rows into a tree table
          ⬇ convert the tree table and system messages into lines
          ⬇ convert each line into a progress message with an index
   ╭────────────────╮
   │Message Renderer│
   ╰────────────────╯
          ⬇ if the line identified in a progress message has changed,
          ⬇ go to that line on the terminal, clear it, and update it
      ╭────────╮
      │Terminal│
      ╰────────╯
```

This separation of concerns is unnecessary and makes it difficult to
understand where and when the terminal is updated. This approach also
makes it somewhat challenging to change the way in which the display
interacts with the terminal, as both the display renderer and the
message renderer need to e.g. understand terminal dimensions, movement,
etc.

These changes reimplement the interactive Progress Renderer using a
frame-oriented approach. The display is updated at 60 frame per second.
If nothing has happened to invalidate the display's contents (i.e. no
changes to the terminal geometry or the displayable contents have occurred),
then the frame is not redrawn. Otherwise, the contents of the display
are re-rendered and redrawn.

An advantage of this approach is that it made it relatively simple to
fix a long-standing issue with the interactive display: when the number
of rows in the output exceed the height of the terminal, the new
renderer clamps the output and allows the user to scroll the tree table
using the up and down arrow keys.

Co-authored-by: Pat Gavlin <pat@pulumi.com>

changelog/pending/20221101--cli-display--improve-the-usability-of-the-interactive-dipslay-by-making-the-treetable-scrollable.yaml

@@ -0,0 +1,4 @@
+changes:
+- type: feat
+  scope: cli/display
+  description: Improve the usability of the interactive dipslay by making the treetable scrollable

pkg/backend/display/jsonmessage.go

@@ -140,14 +140,37 @@ type messageRenderer struct {
 	nonInteractiveSpinner cmdutil.Spinner
 
 	progressOutput chan<- Progress
+	closed         <-chan bool
 
 	// Cache of lines we've already printed.  We don't print a progress message again if it hasn't
 	// changed between the last time we printed and now.
 	printedProgressCache map[string]Progress
 }
 
+func newMessageRenderer(stdout io.Writer, op string, opts Options) progressRenderer {
+	progressOutput, closed := make(chan Progress), make(chan bool)
+	go func() {
+		ShowProgressOutput(progressOutput, stdout, false)
+		close(closed)
+	}()
+
+	spinner, ticker := cmdutil.NewSpinnerAndTicker(
+		fmt.Sprintf("%s%s...", cmdutil.EmojiOr("✨ ", "@ "), op),
+		nil, opts.Color, 1 /*timesPerSecond*/)
+	ticker.Stop()
+
+	return &messageRenderer{
+		opts:                  opts,
+		progressOutput:        progressOutput,
+		closed:                closed,
+		printedProgressCache:  make(map[string]Progress),
+		nonInteractiveSpinner: spinner,
+	}
+}
+
 func (r *messageRenderer) Close() error {
 	close(r.progressOutput)
+	<-r.closed
 	return nil
 }
 
@@ -196,7 +219,7 @@ func (r *messageRenderer) println(display *ProgressDisplay, line string) {
 
 func (r *messageRenderer) tick(display *ProgressDisplay) {
 	if r.isTerminal {
-		r.render(display)
+		r.render(display, false)
 	} else {
 		// Update the spinner to let the user know that that work is still happening.
 		r.nonInteractiveSpinner.Tick()
@@ -233,7 +256,7 @@ func (r *messageRenderer) renderRow(display *ProgressDisplay,
 func (r *messageRenderer) rowUpdated(display *ProgressDisplay, row Row) {
 	if r.isTerminal {
 		// if we're in a terminal, then refresh everything so that all our columns line up
-		r.render(display)
+		r.render(display, false)
 	} else {
 		// otherwise, just print out this single row.
 		colorizedColumns := row.ColorizedColumns()
@@ -246,17 +269,20 @@ func (r *messageRenderer) systemMessage(display *ProgressDisplay, payload engine
 	if r.isTerminal {
 		// if we're in a terminal, then refresh everything.  The system events will come after
 		// all the normal rows
-		r.render(display)
+		r.render(display, false)
 	} else {
 		// otherwise, in a non-terminal, just print out the actual event.
 		r.writeSimpleMessage(renderStdoutColorEvent(payload, display.opts))
 	}
 }
 
 func (r *messageRenderer) done(display *ProgressDisplay) {
+	if r.isTerminal {
+		r.render(display, false)
+	}
 }
 
-func (r *messageRenderer) render(display *ProgressDisplay) {
+func (r *messageRenderer) render(display *ProgressDisplay, done bool) {
 	if !r.isTerminal || display.headerRow == nil {
 		return
 	}
@@ -316,6 +342,10 @@ func (r *messageRenderer) render(display *ProgressDisplay) {
 			systemID++
 		}
 	}
+
+	if done {
+		r.println(display, "")
+	}
 }
 
 // Ensure our stored dimension info is up to date.

pkg/backend/display/options.go

@@ -50,6 +50,7 @@ type Options struct {
 	JSONDisplay          bool                // true if we should emit the entire diff as JSON.
 	EventLogPath         string              // the path to the file to use for logging events, if any.
 	Debug                bool                // true to enable debug output.
+	Stdin                io.Reader           // the reader to use for stdin. Defaults to os.Stdin if unset.
 	Stdout               io.Writer           // the writer to use for stdout. Defaults to os.Stdout if unset.
 	Stderr               io.Writer           // the writer to use for stderr. Defaults to os.Stderr if unset.
 	SuppressTimings      bool                // true to suppress displaying timings of resource actions

pkg/backend/display/progress.go

@@ -19,17 +19,13 @@ import (
 	"bytes"
 	"fmt"
 	"io"
-	"math"
 	"os"
 	"sort"
 	"strings"
 	"time"
 	"unicode"
 	"unicode/utf8"
 
-	"github.com/moby/term"
-	"golang.org/x/crypto/ssh/terminal"
-
 	"github.com/pulumi/pulumi/pkg/v3/engine"
 	"github.com/pulumi/pulumi/pkg/v3/resource/deploy"
 	"github.com/pulumi/pulumi/sdk/v3/go/common/apitype"
@@ -228,45 +224,26 @@ func getEventUrnAndMetadata(event engine.Event) (resource.URN, *engine.StepEvent
 func ShowProgressEvents(op string, action apitype.UpdateKind, stack tokens.Name, proj tokens.PackageName,
 	events <-chan engine.Event, done chan<- bool, opts Options, isPreview bool) {
 
+	stdin := opts.Stdin
+	if stdin == nil {
+		stdin = os.Stdin
+	}
 	stdout := opts.Stdout
 	if stdout == nil {
 		stdout = os.Stdout
 	}
-	stderr := opts.Stderr
-	if stderr == nil {
-		stderr = os.Stderr
-	}
-
-	// Create a ticker that will update all our status messages once a second.  Any
-	// in-flight resources will get a varying .  ..  ... ticker appended to them to
-	// let the user know what is still being worked on.
-	var spinner cmdutil.Spinner
-	var ticker *time.Ticker
-	if stdout == os.Stdout && stderr == os.Stderr {
-		spinner, ticker = cmdutil.NewSpinnerAndTicker(
-			fmt.Sprintf("%s%s...", cmdutil.EmojiOr("✨ ", "@ "), op),
-			nil, opts.Color, 1 /*timesPerSecond*/)
-	} else {
-		spinner = &nopSpinner{}
-		ticker = time.NewTicker(math.MaxInt64)
-	}
-
-	// The channel we push progress messages into, and which ShowProgressOutput pulls
-	// from to display to the console.
-	progressOutput := make(chan Progress)
-
-	opStopwatch := newOpStopwatch()
 
-	renderer := &messageRenderer{
-		opts:                  opts,
-		progressOutput:        progressOutput,
-		printedProgressCache:  make(map[string]Progress),
-		nonInteractiveSpinner: spinner,
+	isTerminal := true
+	renderer, err := newTreeRenderer(stdin, stdout, opts)
+	if err != nil {
+		fmt.Println(err)
+		isTerminal, renderer = false, newMessageRenderer(stdout, op, opts)
 	}
 
 	display := &ProgressDisplay{
 		action:                 action,
 		isPreview:              isPreview,
+		isTerminal:             isTerminal,
 		opts:                   opts,
 		renderer:               renderer,
 		stack:                  stack,
@@ -277,39 +254,12 @@ func ShowProgressEvents(op string, action apitype.UpdateKind, stack tokens.Name,
 		urnToID:                make(map[resource.URN]string),
 		colorizedToUncolorized: make(map[string]string),
 		displayOrderCounter:    1,
-		opStopwatch:            opStopwatch,
+		opStopwatch:            newOpStopwatch(),
 	}
 
-	// Assume we are not displaying in a terminal by default.
-	renderer.isTerminal = false
-	if stdout == os.Stdout {
-		terminalWidth, terminalHeight, err := terminal.GetSize(int(os.Stdout.Fd()))
-		if err == nil {
-			// If the terminal has a size, use it.
-			renderer.isTerminal = opts.IsInteractive
-			renderer.terminalWidth = terminalWidth
-			renderer.terminalHeight = terminalHeight
-
-			// Don't bother attempting to treat this display as a terminal if it has no width/height.
-			if renderer.isTerminal && (renderer.terminalWidth == 0 || renderer.terminalHeight == 0) {
-				renderer.isTerminal = false
-				_, err = fmt.Fprintln(stderr, "Treating display as non-terminal due to 0 width/height.")
-				contract.IgnoreError(err)
-			}
-
-			// Fetch the canonical stdout stream, configured appropriately.
-			_, stdout, _ = term.StdStreams()
-		}
-	}
-	display.isTerminal = renderer.isTerminal
-
-	go func() {
-		display.processEvents(ticker, events)
-		contract.IgnoreClose(display.renderer)
-	}()
-
-	ShowProgressOutput(progressOutput, stdout, display.isTerminal)
-
+	ticker := time.NewTicker(1 * time.Second)
+	display.processEvents(ticker, events)
+	contract.IgnoreClose(display.renderer)
 	ticker.Stop()
 
 	// let our caller know we're done.