fix(cli): show sync wait dependencies (#25089)

## Problem
`coder exp sync want` and `coder exp sync start` both printed generic
success messages, which hid the dependency units involved in startup
coordination.

Before, declaring dependencies with `sync want` printed:

```text
Success
```

Before, `sync start` printed while waiting, then finished with another
generic success message:

```text
Waiting for dependencies of unit 'test-unit' to be satisfied...
Success
```

## Solution
Print the dependency units in both cases, using wording that matches
where the command is in the lifecycle.

After, `sync want` prints the dependencies it declared for the unit:

```text
Unit "test-unit" declared dependencies: [dep-unit]
```

After, `sync start` enumerates the dependencies while it is waiting,
then prints the same dependencies after the unit starts executing:

```text
Unit "test-unit" is waiting for dependencies to be satisfied: [dep-unit, dep-unit-2]
Unit "test-unit" finished waiting for dependencies: [dep-unit, dep-unit-2]
```

The sync golden tests now cover the updated output, including multiple
dependencies for `sync start`.

cli/sync_start.go

@@ -2,6 +2,9 @@ package cli
 
 import (
 	"context"
+	"fmt"
+	"slices"
+	"strings"
 	"time"
 
 	"golang.org/x/xerrors"
@@ -48,13 +51,23 @@ func (*RootCmd) syncStart(socketPath *string) *serpent.Command {
 			}
 			defer client.Close()
 
-			ready, err := client.SyncReady(ctx, unitName)
+			statusResp, err := client.SyncStatus(ctx, unitName)
 			if err != nil {
-				return xerrors.Errorf("error checking dependencies: %w", err)
+				return xerrors.Errorf("get status failed: %w", err)
 			}
+			ready := statusResp.IsReady
 
+			var waitedFor []string
 			if !ready {
-				cliui.Infof(i.Stdout, "Waiting for dependencies of unit '%s' to be satisfied...", unitName)
+				for _, dep := range statusResp.Dependencies {
+					if !dep.IsSatisfied {
+						waitedFor = append(waitedFor, string(dep.DependsOn))
+					}
+				}
+				slices.Sort(waitedFor)
+				waitedForList := strings.Join(waitedFor, ", ")
+
+				cliui.Infof(i.Stdout, "Unit %q is waiting for dependencies to be satisfied: [%s]", unitName, waitedForList)
 
 				ticker := time.NewTicker(syncPollInterval)
 				defer ticker.Stop()
@@ -83,7 +96,11 @@ func (*RootCmd) syncStart(socketPath *string) *serpent.Command {
 				return xerrors.Errorf("start unit failed: %w", err)
 			}
 
+			if len(waitedFor) == 0 {
 				cliui.Info(i.Stdout, "Success")
+			} else {
+				cliui.Info(i.Stdout, fmt.Sprintf("Unit %q finished waiting for dependencies: [%s]", unitName, strings.Join(waitedFor, ", ")))
+			}
 
 			return nil
 		},

cli/sync_test.go

@@ -93,19 +93,20 @@ func TestSyncCommands_Golden(t *testing.T) {
 
 		ctx := testutil.Context(t, testutil.WaitShort)
 
-		// Set up dependency: test-unit depends on dep-unit
+		// Set up dependencies: test-unit depends on dep-unit and dep-unit-2.
 		client, err := agentsocket.NewClient(ctx, agentsocket.WithPath(path))
 		require.NoError(t, err)
 
-		// Declare dependency
 		err = client.SyncWant(ctx, "test-unit", "dep-unit")
 		require.NoError(t, err)
+		err = client.SyncWant(ctx, "test-unit", "dep-unit-2")
+		require.NoError(t, err)
 		client.Close()
 
 		outBuf := testutil.NewWaitBuffer()
 		done := make(chan error, 1)
 		go func() {
-			if err := outBuf.WaitFor(ctx, "Waiting"); err != nil {
+			if err := outBuf.WaitFor(ctx, "is waiting for dependencies"); err != nil {
 				done <- err
 				return
 			}
@@ -118,13 +119,23 @@ func TestSyncCommands_Golden(t *testing.T) {
 			}
 			defer compClient.Close()
 
-			// Start and complete the dependency unit.
+			// Start and complete both dependency units.
 			err = compClient.SyncStart(compCtx, "dep-unit")
 			if err != nil {
 				done <- err
 				return
 			}
 			err = compClient.SyncComplete(compCtx, "dep-unit")
+			if err != nil {
+				done <- err
+				return
+			}
+			err = compClient.SyncStart(compCtx, "dep-unit-2")
+			if err != nil {
+				done <- err
+				return
+			}
+			err = compClient.SyncComplete(compCtx, "dep-unit-2")
 			done <- err
 		}()
 
@@ -132,7 +143,7 @@ func TestSyncCommands_Golden(t *testing.T) {
 		inv.Stdout = outBuf
 		inv.Stderr = outBuf
 
-		// Run the start command - it should wait for the dependency.
+		// Run the start command. It should wait for the dependencies.
 		err = inv.WithContext(ctx).Run()
 		require.NoError(t, err)
 
@@ -179,6 +190,10 @@ func TestSyncCommands_Golden(t *testing.T) {
 
 		err := inv.WithContext(ctx).Run()
 		require.NoError(t, err)
+		require.Contains(t, outBuf.String(), "Unit \"test-unit\" declared dependencies: [dep-1, dep-2, dep-3]")
+		require.Contains(t, outBuf.String(), "dep-1")
+		require.Contains(t, outBuf.String(), "dep-2")
+		require.Contains(t, outBuf.String(), "dep-3")
 
 		// Verify all dependencies were registered by checking status.
 		outBuf.Reset()

cli/sync_want.go

@@ -1,6 +1,9 @@
 package cli
 
 import (
+	"fmt"
+	"strings"
+
 	"golang.org/x/xerrors"
 
 	"github.com/coder/coder/v2/agent/agentsocket"
@@ -39,7 +42,7 @@ func (*RootCmd) syncWant(socketPath *string) *serpent.Command {
 				}
 			}
 
-			cliui.Info(i.Stdout, "Success")
+			cliui.Info(i.Stdout, fmt.Sprintf("Unit %q declared dependencies: [%s]", dependentUnit, strings.Join(i.Args[1:], ", ")))
 
 			return nil
 		},

cli/testdata/TestSyncCommands_Golden/start_with_dependencies.golden

@@ -1,2 +1,2 @@
-Waiting for dependencies of unit 'test-unit' to be satisfied...
-Success
+Unit "test-unit" is waiting for dependencies to be satisfied: [dep-unit, dep-unit-2]
+Unit "test-unit" finished waiting for dependencies: [dep-unit, dep-unit-2]

cli/testdata/TestSyncCommands_Golden/want_success.golden

@@ -1 +1 @@
-Success
+Unit "test-unit" declared dependencies: [dep-unit]