fix(tui): preserve shell preview boundaries

packages/tui/src/routes/session/index.tsx

@@ -66,7 +66,7 @@ import { useConfig } from "../../config"
 import { useClipboard } from "../../context/clipboard"
 import { nextThinkingMode, reasoningSummary, type ThinkingMode } from "../../context/thinking"
 import { getScrollAcceleration } from "../../util/scroll"
-import { collapseToolOutput } from "../../util/collapse-tool-output"
+import { collapseToolOutput, collapseToolOutputParts } from "../../util/collapse-tool-output"
 import { usePluginRuntime } from "../../plugin/runtime"
 import { OPENCODE_BASE_MODE, useBindings, useCommandShortcut } from "../../keymap"
 import { usePathFormatter } from "../../context/path-format"
@@ -2384,16 +2384,10 @@ function Shell(props: ToolProps) {
   const maxLines = 10
   const maxChars = createMemo(() => maxLines * Math.max(20, ctx.width - 6))
   const input = createMemo(() => (command() ? `${isRunning() ? "" : "$ "}${command()}` : ""))
-  const content = createMemo(() => [input(), output()].filter(Boolean).join("\n\n"))
-  const collapsed = createMemo(() => collapseToolOutput(content(), maxLines, maxChars()))
+  const collapsed = createMemo(() => collapseToolOutputParts(input(), output(), maxLines, maxChars()))
   const visible = createMemo(() => {
-    const command = input()
-    if (expanded()) return { input: command, output: output() }
-    const preview = collapsed().overflow ? collapsed().output : content()
-    return {
-      input: preview.slice(0, command.length),
-      output: preview.slice(command.length).replace(/^\n+/, ""),
-    }
+    if (expanded()) return { input: input(), output: output() }
+    return collapsed()
   })
   const expandable = createMemo(() => Boolean(shellID()) || collapsed().overflow)
   const toggle = () => {

packages/tui/src/util/collapse-tool-output.ts

@@ -19,3 +19,26 @@ export function collapseToolOutput(output: string, maxLines: number, maxChars: n
 
   return { output: preview, overflow: true }
 }
+
+export function collapseToolOutputParts(input: string, output: string, maxLines: number, maxChars: number) {
+  const separator = input && output ? "\n\n" : ""
+  const collapsed = collapseToolOutput(`${input}${separator}${output}`, maxLines, maxChars)
+  if (!collapsed.overflow) return { input, output, overflow: false }
+
+  const ellipsis = collapsed.output.endsWith("…") ? "…" : ""
+  const preview = ellipsis ? collapsed.output.slice(0, -1) : collapsed.output
+  const outputStart = input.length + separator.length
+  if (preview.length <= outputStart) {
+    return {
+      input: preview.slice(0, input.length) + ellipsis,
+      output: "",
+      overflow: true,
+    }
+  }
+
+  return {
+    input,
+    output: preview.slice(outputStart) + ellipsis,
+    overflow: true,
+  }
+}

packages/tui/test/cli/tui/collapse-tool-output.test.ts

@@ -1,5 +1,5 @@
 import { expect, test } from "bun:test"
-import { collapseToolOutput } from "../../../src/util/collapse-tool-output"
+import { collapseToolOutput, collapseToolOutputParts } from "../../../src/util/collapse-tool-output"
 
 test("limits command input and output to the same line budget", () => {
   const command = Array.from({ length: 8 }, (_, index) => `command ${index + 1}`).join("\n")
@@ -12,3 +12,33 @@ test("limits command input and output to the same line budget", () => {
   expect(collapsed.output).toContain("command 8\n\noutput 1…")
   expect(collapsed.output).not.toContain("output 2")
 })
+
+test.each([
+  {
+    name: "inside the command",
+    maxChars: 5,
+    expected: { input: "$ co…", output: "", overflow: true },
+  },
+  {
+    name: "after the command",
+    maxChars: 10,
+    expected: { input: "$ command…", output: "", overflow: true },
+  },
+  {
+    name: "on the first separator newline",
+    maxChars: 11,
+    expected: { input: "$ command…", output: "", overflow: true },
+  },
+  {
+    name: "on the second separator newline",
+    maxChars: 12,
+    expected: { input: "$ command…", output: "", overflow: true },
+  },
+  {
+    name: "inside the output",
+    maxChars: 15,
+    expected: { input: "$ command", output: "out…", overflow: true },
+  },
+])("keeps the ellipsis with the visible $name", ({ maxChars, expected }) => {
+  expect(collapseToolOutputParts("$ command", "output", 10, maxChars)).toEqual(expected)
+})