test: reproduce Starship prompt going static in bash sessions

The bash bootstrap Programa injects as PROMPT_COMMAND begins with
unset PROMPT_COMMAND. When a user's startup files run
eval "$(starship init bash)" before the first prompt, that appends
starship_precmd to PROMPT_COMMAND; the bootstrap's unset then throws it
away after running once, so the Starship prompt stops updating after
the first command.

Extract the bootstrap into its own file
(Resources/shell-integration/programa-bash-bootstrap.bash) so the app
and the test share one source of truth, and add a regression test that
drives the real bootstrap plus a Starship-shaped prompt hook through
bash. This keeps the current buggy behavior so CI shows the new test
red; the fix follows in the next commit.

Author: arzafran

Resources/shell-integration/programa-bash-bootstrap.bash

@@ -0,0 +1,22 @@
+# Programa bash prompt bootstrap.
+#
+# macOS ships /bin/bash 3.2, where Ghostty's automatic bash integration is
+# unsupported and HOME-based wrapper startup is not reliable. Programa instead
+# exports this script as PROMPT_COMMAND so it runs once on the first
+# interactive prompt: it sources Programa's bash integration and then hands
+# control to _programa_prompt_command.
+#
+# This file is the single source of truth. Sources/GhosttyTerminalView.swift
+# reads it (stripping these comments) and exports it as PROMPT_COMMAND, and
+# programaTests/GhosttyConfigTests.swift exercises it.
+unset PROMPT_COMMAND
+if [[ "${PROGRAMA_LOAD_GHOSTTY_BASH_INTEGRATION:-0}" == "1" && -n "${GHOSTTY_RESOURCES_DIR:-}" ]]; then
+    _programa_ghostty_bash="$GHOSTTY_RESOURCES_DIR/shell-integration/bash/ghostty.bash"
+    [[ -r "$_programa_ghostty_bash" ]] && source "$_programa_ghostty_bash"
+fi
+if [[ "${PROGRAMA_SHELL_INTEGRATION:-1}" != "0" && -n "${PROGRAMA_SHELL_INTEGRATION_DIR:-}" ]]; then
+    _programa_bash_integration="$PROGRAMA_SHELL_INTEGRATION_DIR/programa-bash-integration.bash"
+    [[ -r "$_programa_bash_integration" ]] && source "$_programa_bash_integration"
+fi
+unset _programa_ghostty_bash _programa_bash_integration
+if declare -F _programa_prompt_command >/dev/null 2>&1; then _programa_prompt_command; fi

Sources/GhosttyTerminalView.swift

@@ -4069,21 +4069,27 @@ final class TerminalSurface: Identifiable, ObservableObject {
                 }
                 // macOS ships /bin/bash 3.2, where Ghostty's automatic bash
                 // integration is unsupported and HOME-based wrapper startup is
-                // not reliable. Bootstrap cmux bash integration on the first
-                // interactive prompt instead.
-                setManagedEnvironmentValue("PROMPT_COMMAND", """
-                unset PROMPT_COMMAND; \
-                if [[ "${PROGRAMA_LOAD_GHOSTTY_BASH_INTEGRATION:-0}" == "1" && -n "${GHOSTTY_RESOURCES_DIR:-}" ]]; then \
-                _programa_ghostty_bash="$GHOSTTY_RESOURCES_DIR/shell-integration/bash/ghostty.bash"; \
-                [[ -r "$_programa_ghostty_bash" ]] && source "$_programa_ghostty_bash"; \
-                fi; \
-                if [[ "${PROGRAMA_SHELL_INTEGRATION:-1}" != "0" && -n "${PROGRAMA_SHELL_INTEGRATION_DIR:-}" ]]; then \
-                _programa_bash_integration="$PROGRAMA_SHELL_INTEGRATION_DIR/programa-bash-integration.bash"; \
-                [[ -r "$_programa_bash_integration" ]] && source "$_programa_bash_integration"; \
-                fi; \
-                unset _programa_ghostty_bash _programa_bash_integration; \
-                if declare -F _programa_prompt_command >/dev/null 2>&1; then _programa_prompt_command; fi
-                """)
+                // not reliable. Bootstrap Programa bash integration on the
+                // first interactive prompt by exporting the shared bootstrap
+                // script as PROMPT_COMMAND. The script lives in
+                // Resources/shell-integration so the app and the regression
+                // test share one source of truth. Doc comments and blank
+                // lines are stripped so users never see them in
+                // $PROMPT_COMMAND; the test mirrors this.
+                let bashBootstrapPath = (integrationDir as NSString)
+                    .appendingPathComponent("programa-bash-bootstrap.bash")
+                if let rawBootstrap = try? String(contentsOfFile: bashBootstrapPath, encoding: .utf8) {
+                    let bootstrap = rawBootstrap
+                        .components(separatedBy: "\n")
+                        .filter { line in
+                            let trimmed = line.trimmingCharacters(in: .whitespacesAndNewlines)
+                            return !trimmed.isEmpty && !trimmed.hasPrefix("#")
+                        }
+                        .joined(separator: "\n")
+                    if !bootstrap.isEmpty {
+                        setManagedEnvironmentValue("PROMPT_COMMAND", bootstrap)
+                    }
+                }
             }
         }
         env = Self.mergedStartupEnvironment(

programaTests/GhosttyConfigTests.swift

@@ -3345,6 +3345,179 @@ final class ZshShellIntegrationHandoffTests: XCTestCase {
         )
     }
 
+    func testBashBootstrapPreservesStarshipPromptCommandAcrossPrompts() throws {
+        // Regression test: Programa's local macOS bash bootstrap is injected
+        // as PROMPT_COMMAND and used to begin by unconditionally clobbering
+        // PROMPT_COMMAND. A user's startup files run
+        // `eval "$(starship init bash)"` before the first prompt, which
+        // appends starship_precmd to PROMPT_COMMAND; the bootstrap then
+        // discarded it after running once, freezing the prompt. This drives
+        // the real bootstrap file (Resources/shell-integration/
+        // programa-bash-bootstrap.bash) plus a faithful starship stub
+        // through bash and asserts starship_precmd survives across prompts,
+        // rather than relying on a PTY.
+        let fields = try runBashBootstrapDriver(withUserPromptHook: true)
+        let debug = "\n\nstdout:\n\(fields["__stdout__"] ?? "")\nstderr:\n\(fields["__stderr__"] ?? "")"
+
+        XCTAssertTrue(
+            (fields["PC_AFTER_RC"] ?? "").contains("starship_precmd"),
+            "test setup did not append starship_precmd to PROMPT_COMMAND" + debug
+        )
+
+        for i in 1...3 {
+            let pc = fields["PC_\(i)"] ?? ""
+            XCTAssertTrue(
+                pc.contains("starship_precmd"),
+                "starship_precmd was dropped from PROMPT_COMMAND at prompt \(i); the bootstrap took exclusive ownership instead of composing with the user's hook. PROMPT_COMMAND=<\(pc)>" + debug
+            )
+            XCTAssertTrue(
+                pc.contains("_cmux_prompt_command"),
+                "Programa's own prompt hook is missing from PROMPT_COMMAND at prompt \(i): <\(pc)>" + debug
+            )
+        }
+
+        let ps1Values = (1...3).map { fields["PS1_\($0)"] ?? "" }
+        XCTAssertNotEqual(
+            ps1Values[0], ps1Values[1],
+            "starship prompt went static across prompts (it stopped re-rendering): \(ps1Values)" + debug
+        )
+        XCTAssertNotEqual(
+            ps1Values[1], ps1Values[2],
+            "starship prompt went static across prompts (it stopped re-rendering): \(ps1Values)" + debug
+        )
+        XCTAssertTrue(
+            ps1Values[2].contains("n=3"),
+            "starship_precmd did not run on every prompt; final PS1=<\(ps1Values[2])>" + debug
+        )
+        XCTAssertTrue(
+            ps1Values[2].contains("cwd=cd-target"),
+            "prompt did not pick up the new cwd after cd; final PS1=<\(ps1Values[2])>" + debug
+        )
+    }
+
+    /// Drives `Resources/shell-integration/programa-bash-bootstrap.bash`
+    /// through real bash, modeling bash's "evaluate PROMPT_COMMAND before
+    /// each prompt" loop directly (deterministic, no PTY needed). When
+    /// `withUserPromptHook` is true, simulates a user's startup files running
+    /// `eval "$(starship init bash)"` and appending `starship_precmd` to
+    /// PROMPT_COMMAND before the first prompt, exactly as the real Starship
+    /// binary's bash init does for non-bash-preexec shells.
+    private func runBashBootstrapDriver(withUserPromptHook: Bool) throws -> [String: String] {
+        let fileManager = FileManager.default
+        let repoRoot = URL(fileURLWithPath: #filePath)
+            .deletingLastPathComponent()
+            .deletingLastPathComponent()
+        let bootstrapSourcePath = repoRoot
+            .appendingPathComponent("Resources/shell-integration/programa-bash-bootstrap.bash")
+        let rawBootstrap = try String(contentsOf: bootstrapSourcePath, encoding: .utf8)
+        // Mirrors Sources/GhosttyTerminalView.swift's comment/blank-line
+        // stripping so the test exercises exactly what ships as
+        // $PROMPT_COMMAND.
+        let leanBootstrap = rawBootstrap
+            .components(separatedBy: "\n")
+            .filter { line in
+                let trimmed = line.trimmingCharacters(in: .whitespacesAndNewlines)
+                return !trimmed.isEmpty && !trimmed.hasPrefix("#")
+            }
+            .joined(separator: "\n")
+
+        let root = fileManager.temporaryDirectory
+            .appendingPathComponent("cmux-bash-bootstrap-starship-\(UUID().uuidString)")
+        try fileManager.createDirectory(at: root, withIntermediateDirectories: true)
+        defer { try? fileManager.removeItem(at: root) }
+
+        let bootstrapFile = root.appendingPathComponent("bootstrap.bash")
+        try leanBootstrap.write(to: bootstrapFile, atomically: true, encoding: .utf8)
+
+        let cdTarget = root.appendingPathComponent("cd-target")
+        try fileManager.createDirectory(at: cdTarget, withIntermediateDirectories: true)
+
+        let shellIntegrationDir = repoRoot.appendingPathComponent("Resources/shell-integration")
+
+        let driver = #"""
+        set +e
+        PROMPT_COMMAND="$(cat "$BOOTSTRAP_FILE")"
+
+        if [[ "${WITH_USER_HOOK:-1}" == "1" ]]; then
+            starship_precmd() {
+                STARSHIP_COUNTER=$((STARSHIP_COUNTER + 1))
+                PS1="cwd=${PWD##*/} n=${STARSHIP_COUNTER} "
+            }
+            if [[ "$(declare -p PROMPT_COMMAND 2>/dev/null)" == "declare -a"* ]]; then
+                PROMPT_COMMAND+=(starship_precmd)
+            else
+                PROMPT_COMMAND=${PROMPT_COMMAND:+$PROMPT_COMMAND$'\n'}"starship_precmd"
+            fi
+        fi
+
+        _emit() { printf '%s<%s>\n' "$1" "${2//$'\n'/<NL>}"; }
+        _emit PC_AFTER_RC "$PROMPT_COMMAND"
+
+        _render() {
+            if [[ "$(declare -p PROMPT_COMMAND 2>/dev/null)" == "declare -a"* ]]; then
+                local pc
+                for pc in "${PROMPT_COMMAND[@]}"; do eval "$pc"; done
+            else
+                eval "$PROMPT_COMMAND"
+            fi
+        }
+
+        STARSHIP_COUNTER=0
+        i=0
+        while (( i < 3 )); do
+            i=$((i + 1))
+            (( i == 3 )) && cd "$CD_TARGET"
+            _render
+            _emit "PS1_$i" "$PS1"
+            _emit "PC_$i" "$PROMPT_COMMAND"
+        done
+        """#
+
+        let process = Process()
+        process.executableURL = URL(fileURLWithPath: "/bin/bash")
+        process.arguments = ["--noprofile", "--norc", "-c", driver]
+        process.environment = [
+            "HOME": root.path,
+            "PATH": "/usr/bin:/bin:/usr/sbin:/sbin",
+            "BOOTSTRAP_FILE": bootstrapFile.path,
+            "CD_TARGET": cdTarget.path,
+            "WITH_USER_HOOK": withUserPromptHook ? "1" : "0",
+            "PROGRAMA_LOAD_GHOSTTY_BASH_INTEGRATION": "0",
+            "GHOSTTY_RESOURCES_DIR": "",
+            "PROGRAMA_SHELL_INTEGRATION": "1",
+            "PROGRAMA_SHELL_INTEGRATION_DIR": shellIntegrationDir.path,
+        ]
+
+        let stdout = Pipe()
+        let stderr = Pipe()
+        process.standardOutput = stdout
+        process.standardError = stderr
+
+        try process.run()
+        let deadline = Date().addingTimeInterval(5)
+        while process.isRunning && Date() < deadline {
+            _ = RunLoop.current.run(mode: .default, before: Date().addingTimeInterval(0.01))
+        }
+        if process.isRunning {
+            process.terminate()
+            process.waitUntilExit()
+            XCTFail("Timed out waiting for bash bootstrap driver to exit")
+        }
+
+        let output = String(data: stdout.fileHandleForReading.readDataToEndOfFile(), encoding: .utf8) ?? ""
+        let error = String(data: stderr.fileHandleForReading.readDataToEndOfFile(), encoding: .utf8) ?? ""
+        XCTAssertEqual(process.terminationStatus, 0, "stdout:\n\(output)\nstderr:\n\(error)")
+
+        var fields: [String: String] = ["__stdout__": output, "__stderr__": error]
+        for line in output.split(separator: "\n", omittingEmptySubsequences: true) {
+            guard let openIdx = line.firstIndex(of: "<"), line.hasSuffix(">") else { continue }
+            let key = String(line[line.startIndex..<openIdx])
+            let value = String(line[line.index(after: openIdx)..<line.index(before: line.endIndex)])
+            fields[key] = value
+        }
+        return fields
+    }
+
     private func runInteractiveZsh(cmuxLoadGhosttyIntegration: Bool) throws -> String {
         try runInteractiveZsh(
             cmuxLoadGhosttyIntegration: cmuxLoadGhosttyIntegration,