Keep set-buffer text exact and read it from stdin

CLI/CMUXCLI+TaskHelp.swift

@@ -428,7 +428,7 @@ extension CMUXCLI {
         set-hook [--list] [--unset <event>] | <event> <command>
         popup
         bind-key | unbind-key | copy-mode
-        set-buffer [--name <name>] <text>
+        set-buffer [--name <name>] [<text> | -]
         list-buffers
         paste-buffer [--name <name>] [--workspace <id|ref|index>] [--surface <id|ref|index>] [--window <id|ref|index>]
         respawn-pane [--workspace <id|ref|index>] [--surface <id|ref|index>] [--window <id|ref|index>] [--command <cmd>]

CLI/cmux.swift

@@ -19826,9 +19826,9 @@ struct CMUXCLI {
             """
         case "set-buffer":
             return """
-            Usage: cmux set-buffer [--name <name>] [--] <text>
+            Usage: cmux set-buffer [--name <name>] [--] [<text> | -]
 
-            Save text into a named tmux-compat buffer.
+            Save text into a named tmux-compat buffer, exactly as given. With no text argument, or with -, the text is read from stdin.
 
             Flags:
               --name <name>   Buffer name (default: default)
@@ -27359,7 +27359,27 @@ struct CMUXCLI {
         case "set-buffer":
             let (nameArg, rem0) = parseOption(commandArgs, name: "--name")
             let name = (nameArg?.trimmingCharacters(in: .whitespacesAndNewlines).isEmpty == false) ? nameArg! : "default"
-            let content = rem0.dropFirst(rem0.first == "--" ? 1 : 0).joined(separator: " ").trimmingCharacters(in: .whitespacesAndNewlines)
+            // Store the text exactly as given, like tmux: trailing newlines and
+            // indentation are part of what paste-buffer should deliver. With no
+            // text argument, or a lone "-", read the text from stdin so output
+            // can be piped in (`cmd | cmux set-buffer`).
+            let textArgs = Array(rem0.dropFirst(rem0.first == "--" ? 1 : 0))
+            let content: String
+            if textArgs.isEmpty || textArgs == ["-"] {
+                guard isatty(STDIN_FILENO) != 1 else {
+                    throw CLIError(message: "set-buffer requires text")
+                }
+                let data = FileHandle.standardInput.readDataToEndOfFile()
+                guard let text = String(data: data, encoding: .utf8) else {
+                    throw CLIError(message: String(
+                        localized: "cli.setBuffer.error.invalidUTF8",
+                        defaultValue: "set-buffer: stdin is not valid UTF-8 text"
+                    ))
+                }
+                content = text
+            } else {
+                content = textArgs.joined(separator: " ")
+            }
             guard !content.isEmpty else {
                 throw CLIError(message: "set-buffer requires text")
             }

Resources/Localizable.xcstrings

@@ -558407,6 +558407,65 @@
           }
         }
       }
+    },
+    "cli.setBuffer.error.invalidUTF8": {
+      "extractionState": "manual",
+      "localizations": {
+        "en": {
+          "stringUnit": {
+            "state": "translated",
+            "value": "set-buffer: stdin is not valid UTF-8 text"
+          }
+        },
+        "ar": {
+          "stringUnit": {
+            "state": "translated",
+            "value": "set-buffer: محتوى stdin ليس نص UTF-8 صالحًا"
+          }
+        },
+        "de": {
+          "stringUnit": {
+            "state": "translated",
+            "value": "set-buffer: stdin ist kein gültiger UTF-8-Text"
+          }
+        },
+        "es": {
+          "stringUnit": {
+            "state": "translated",
+            "value": "set-buffer: stdin no es texto UTF-8 válido"
+          }
+        },
+        "fr": {
+          "stringUnit": {
+            "state": "translated",
+            "value": "set-buffer : stdin n’est pas un texte UTF-8 valide"
+          }
+        },
+        "ja": {
+          "stringUnit": {
+            "state": "translated",
+            "value": "set-buffer: stdin が有効な UTF-8 テキストではありません"
+          }
+        },
+        "ko": {
+          "stringUnit": {
+            "state": "translated",
+            "value": "set-buffer: stdin이 유효한 UTF-8 텍스트가 아닙니다"
+          }
+        },
+        "zh-Hans": {
+          "stringUnit": {
+            "state": "translated",
+            "value": "set-buffer：stdin 不是有效的 UTF-8 文本"
+          }
+        },
+        "zh-Hant": {
+          "stringUnit": {
+            "state": "translated",
+            "value": "set-buffer：stdin 不是有效的 UTF-8 文字"
+          }
+        }
+      }
     }
   },
   "version": "1.0"

cmux.xcodeproj/project.pbxproj

@@ -643,6 +643,7 @@
 		C11757000000000000000033 /* CLIStdioSIGPIPERegressionTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = C1175700000000000000001A /* CLIStdioSIGPIPERegressionTests.swift */; };
 		C11757000000000000000045 /* CLITestBundleAnchor.swift in Sources */ = {isa = PBXBuildFile; fileRef = C11757000000000000000053 /* CLITestBundleAnchor.swift */; };
 		C11757000000000000000054 /* CLITestBundleAnchor.swift in Sources */ = {isa = PBXBuildFile; fileRef = C11757000000000000000053 /* CLITestBundleAnchor.swift */; };
+		C117570000000000000000B2 /* CLITmuxCompatBufferContentTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = C117570000000000000000B1 /* CLITmuxCompatBufferContentTests.swift */; };
 		B05553B10000000000000001 /* CLITmuxCompatRemoteSplitTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = B05553B10000000000000002 /* CLITmuxCompatRemoteSplitTests.swift */; };
 		7837E0057837E0057837E005 /* CLITmuxCompatResizePaneTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = 7837E0067837E0067837E006 /* CLITmuxCompatResizePaneTests.swift */; };
 		C11757000000000000000034 /* CLITmuxCompatStoreConcurrencyTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = C1175700000000000000001B /* CLITmuxCompatStoreConcurrencyTests.swift */; };
@@ -4745,6 +4746,7 @@
 		A7367002A1B2C3D4E5F60718 /* CLISSHSessionAttachAnchorTests.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = CLISSHSessionAttachAnchorTests.swift; sourceTree = "<group>"; };
 		C1175700000000000000001A /* CLIStdioSIGPIPERegressionTests.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = CLIStdioSIGPIPERegressionTests.swift; sourceTree = "<group>"; };
 		C11757000000000000000053 /* CLITestBundleAnchor.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = CLITestBundleAnchor.swift; sourceTree = "<group>"; };
+		C117570000000000000000B1 /* CLITmuxCompatBufferContentTests.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = CLITmuxCompatBufferContentTests.swift; sourceTree = "<group>"; };
 		B05553B10000000000000002 /* CLITmuxCompatRemoteSplitTests.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = CLITmuxCompatRemoteSplitTests.swift; sourceTree = "<group>"; };
 		7837E0067837E0067837E006 /* CLITmuxCompatResizePaneTests.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = CLITmuxCompatResizePaneTests.swift; sourceTree = "<group>"; };
 		C1175700000000000000001B /* CLITmuxCompatStoreConcurrencyTests.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = CLITmuxCompatStoreConcurrencyTests.swift; sourceTree = "<group>"; };
@@ -8178,6 +8180,7 @@
 				C11757000000000000000019 /* CLISSHPTYResizeInputTests.swift */,
 				C1175700000000000000001A /* CLIStdioSIGPIPERegressionTests.swift */,
 				C1175700000000000000001B /* CLITmuxCompatStoreConcurrencyTests.swift */,
+				C117570000000000000000B1 /* CLITmuxCompatBufferContentTests.swift */,
 				C1175700000000000000001C /* CLIWindowHandleRoutingTests.swift */,
 				C1175700000000000000001D /* CLIWorkspaceGroupSafetyTests.swift */,
 				C1175700000000000000001E /* CLIWorkspaceStableIDTests.swift */,
@@ -12848,6 +12851,7 @@
 				C11757000000000000000032 /* CLISSHPTYResizeInputTests.swift in Sources */,
 				C11757000000000000000033 /* CLIStdioSIGPIPERegressionTests.swift in Sources */,
 				C11757000000000000000045 /* CLITestBundleAnchor.swift in Sources */,
+				C117570000000000000000B2 /* CLITmuxCompatBufferContentTests.swift in Sources */,
 				C11757000000000000000034 /* CLITmuxCompatStoreConcurrencyTests.swift in Sources */,
 				C11757000000000000000046 /* CLIWindowCommandMockServer.swift in Sources */,
 				C11757000000000000000035 /* CLIWindowHandleRoutingTests.swift in Sources */,

cmuxCLITests/CLITmuxCompatBufferContentTests.swift

@@ -0,0 +1,131 @@
+import Darwin
+import Foundation
+import Testing
+
+/// `cmux set-buffer` stores exactly the text it is given, including trailing
+/// newlines and indentation, and reads that text from stdin when no text
+/// argument is passed, so `cmd | cmux set-buffer` works like tmux.
+@Suite(.serialized)
+struct CLITmuxCompatBufferContentTests {
+    @Test func setBufferReadsStandardInputVerbatim() throws {
+        let text = "first line\n  indented line\n\n"
+        let run = try runSetBuffer(arguments: ["set-buffer", "--name", "piped"], standardInput: text)
+
+        #expect(run.result.status == 0, Comment(rawValue: run.result.stderr))
+        #expect(run.buffers?["piped"] == text)
+    }
+
+    @Test func setBufferDashReadsStandardInput() throws {
+        let run = try runSetBuffer(arguments: ["set-buffer", "--name", "dash", "-"], standardInput: "from stdin\n")
+
+        #expect(run.result.status == 0, Comment(rawValue: run.result.stderr))
+        #expect(run.buffers?["dash"] == "from stdin\n")
+    }
+
+    @Test func setBufferKeepsTrailingNewlineAndSpacesFromArguments() throws {
+        let run = try runSetBuffer(arguments: ["set-buffer", "--name", "arg", "--", "  echo hi\n"])
+
+        #expect(run.result.status == 0, Comment(rawValue: run.result.stderr))
+        #expect(run.buffers?["arg"] == "  echo hi\n")
+    }
+
+    @Test func setBufferWithEmptyStandardInputFailsWithoutWriting() throws {
+        let run = try runSetBuffer(arguments: ["set-buffer", "--name", "empty"], standardInput: "")
+
+        #expect(run.result.status != 0)
+        #expect(run.buffers?["empty"] == nil)
+    }
+
+    // MARK: - Harness
+
+    private struct Run {
+        let result: CLIHookProcessRunner.Result
+        let buffers: [String: String]?
+    }
+
+    private func runSetBuffer(arguments: [String], standardInput: String? = nil) throws -> Run {
+        let root = FileManager.default.temporaryDirectory
+            .appendingPathComponent("cmux-tmux-buffer-content-\(UUID().uuidString)", isDirectory: true)
+        let home = root.appendingPathComponent("home", isDirectory: true)
+        let storeURL = home
+            .appendingPathComponent(".cmuxterm", isDirectory: true)
+            .appendingPathComponent("tmux-compat-store.json", isDirectory: false)
+        try FileManager.default.createDirectory(
+            at: storeURL.deletingLastPathComponent(),
+            withIntermediateDirectories: true
+        )
+        defer { try? FileManager.default.removeItem(at: root) }
+
+        let socketPath = makeCodexHookSocketPath("setbuf")
+        let listenerFD = try bindCodexHookUnixSocket(at: socketPath)
+        let drain = Self.startClientDrain(listenerFD: listenerFD)
+        defer {
+            drain.stop.set()
+            _ = drain.done.wait(timeout: .now() + 5)
+            Darwin.close(listenerFD)
+            unlink(socketPath)
+        }
+
+        let result = CLIHookProcessRunner.run(
+            executablePath: try BundledCLITestSupport.bundledCLIPath(for: CLITestBundleAnchor.self),
+            arguments: arguments,
+            environment: [
+                "CMUX_SOCKET_PATH": socketPath,
+                "CMUX_SOCKET_PASSWORD": "",
+                "CMUX_CLI_SENTRY_DISABLED": "1",
+                "CFFIXED_USER_HOME": home.path,
+                "HOME": home.path,
+                "PATH": ProcessInfo.processInfo.environment["PATH"] ?? "/usr/bin:/bin",
+            ],
+            standardInput: standardInput,
+            timeout: 60
+        )
+        #expect(!result.timedOut, Comment(rawValue: result.stderr))
+
+        var buffers: [String: String]?
+        if let data = try? Data(contentsOf: storeURL),
+           let object = try? JSONSerialization.jsonObject(with: data, options: []) as? [String: Any] {
+            buffers = object["buffers"] as? [String: String]
+        }
+        return Run(result: result, buffers: buffers)
+    }
+
+    private final class StopFlag: @unchecked Sendable {
+        private let lock = NSLock()
+        private var value = false
+
+        var isSet: Bool {
+            lock.lock()
+            defer { lock.unlock() }
+            return value
+        }
+
+        func set() {
+            lock.lock()
+            value = true
+            lock.unlock()
+        }
+    }
+
+    /// Accepts and immediately closes clients until stopped; set-buffer only
+    /// touches the local store, so no socket replies are needed.
+    private static func startClientDrain(listenerFD: Int32) -> (done: DispatchSemaphore, stop: StopFlag) {
+        let done = DispatchSemaphore(value: 0)
+        let stop = StopFlag()
+        DispatchQueue.global(qos: .userInitiated).async {
+            defer { done.signal() }
+            while !stop.isSet {
+                var descriptor = pollfd(fd: listenerFD, events: Int16(POLLIN), revents: 0)
+                let ready = Darwin.poll(&descriptor, 1, 100)
+                if ready < 0 {
+                    if errno == EINTR { continue }
+                    return
+                }
+                guard ready > 0 else { continue }
+                let clientFD = Darwin.accept(listenerFD, nil, nil)
+                if clientFD >= 0 { Darwin.close(clientFD) }
+            }
+        }
+        return (done, stop)
+    }
+}

docs/cli-contract.md

@@ -525,7 +525,7 @@ tmux compatibility commands:
 | `set-hook` | Manage tmux-compat hook definitions. |
 | `popup` | Placeholder, currently unsupported. |
 | `bind-key`, `unbind-key`, `copy-mode` | Placeholders, currently unsupported. |
-| `set-buffer` | Set a tmux-compat buffer. |
+| `set-buffer` | Set a tmux-compat buffer to the given text exactly; reads stdin when no text (or `-`) is given. |
 | `paste-buffer` | Paste a tmux-compat buffer. |
 | `list-buffers` | List tmux-compat buffers. |
 | `respawn-pane` | Send a restart command to a surface. |