vtcode-core 0.169.3

Core library for VT Code - a Rust-based terminal coding agent
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143

/// Centralized error messages for tool operations.
///
/// This module provides consistent, reusable error messages across tool
/// implementations to ensure uniformity in user-facing error reporting.
///
/// Only actively-used message groups are retained. Submodules that were
/// defined but never referenced by tool implementations have been removed.
pub mod agent_execution {
    /// Marker used when planning workflow blocks a mutating tool call.
    pub const PLANNING_DENIED_CONTEXT: &str = "tool denied by planning workflow";
    /// Prefix for loop detection failures. Classify a failure with
    /// [`is_loop_detection_block_message`], which matches the whole generated
    /// shape, rather than searching for this prefix inside arbitrary text.
    pub const LOOP_DETECTION_PREFIX: &str = "Loop detection";
    const LOOP_BLOCK_TOOL_OPEN: &str = ": Tool '";
    const LOOP_BLOCK_CALLED: &str = "' has been called ";
    const LOOP_BLOCK_BLOCKED: &str = " times with identical parameters and is now blocked.";
    /// Canonical line stating the consequence of a loop detection block.
    pub const LOOP_RETRY_BLOCKED_LINE: &str =
        "The call was not executed, and repeating it with the same parameters will be blocked again.";

    /// Build the canonical Planning workflow denial message.
    pub fn planning_workflow_denial_message(tool_name: &str) -> String {
        format!(
            "Tool '{tool_name}' execution failed: tool denied by planning workflow\n\n\
             This tool can modify the workspace, so it is blocked during planning.\n\n\
             Available during planning:\n\
             - Read files: exec_command with readonly shell inspection commands such as sed, rg, ls, find, and git show\n\
             - Run readonly commands: cargo check, cargo test, git status, ls, grep, find, diff\n\
             - Search code: exec_command with rg or other readonly search commands\n\
             - Use task_tracker\n\n\
             To start implementation:\n\
             1. Wait for the user to review and approve the plan in the UI\n\
             2. After approval, use apply_patch for file edits\n\n\
             Fallback if automatic planning handoff keeps failing: type `implement` to present the plan again."
        )
    }

    /// Build the canonical loop-detection block message.
    pub fn loop_detection_block_message(tool_name: &str, repeat_count: u64, original_error: Option<&str>) -> String {
        let mut message = format!(
            "{LOOP_DETECTION_PREFIX}{LOOP_BLOCK_TOOL_OPEN}{tool_name}{LOOP_BLOCK_CALLED}{repeat_count}{LOOP_BLOCK_BLOCKED}\n\n\
             {LOOP_RETRY_BLOCKED_LINE}\n\n\
             If you need the result from this tool:\n\
             1. Check if you already have the result from a previous successful call in your conversation history\n\
             2. If not available, use a different approach or modify your request"
        );

        if let Some(error) = original_error {
            message.push_str("\n\nOriginal error: ");
            message.push_str(error);
        }

        message
    }

    /// Whether `message` is a block message built by
    /// [`loop_detection_block_message`]: it must start with the exact
    /// generated opening, `Loop detection: Tool '<name>' has been called <n>
    /// times with identical parameters and is now blocked.`, so tool stderr
    /// or prose that merely mentions loop detection is not classified.
    pub fn is_loop_detection_block_message(message: &str) -> bool {
        let Some(rest) = message
            .strip_prefix(LOOP_DETECTION_PREFIX)
            .and_then(|rest| rest.strip_prefix(LOOP_BLOCK_TOOL_OPEN))
        else {
            return false;
        };
        let Some((tool_name, rest)) = rest.split_once(LOOP_BLOCK_CALLED) else {
            return false;
        };
        let count_len = rest.len() - rest.trim_start_matches(|c: char| c.is_ascii_digit()).len();
        !tool_name.is_empty() && count_len > 0 && rest[count_len..].starts_with(LOOP_BLOCK_BLOCKED)
    }

    /// Check whether an error string corresponds to planning workflow denial.
    pub fn is_planning_active_denial(error: &str) -> bool {
        error.contains(PLANNING_DENIED_CONTEXT)
    }
}

/// Skill management error messages
pub mod skill_ops {
    pub const SKILL_NOT_FOUND: &str = "Skill not found";
    pub const SKILL_ALREADY_EXISTS: &str = "Skill already exists";
    pub const INVALID_SKILL_FORMAT: &str = "Invalid skill format";
    pub const SKILL_SAVE_FAILED: &str = "Failed to save skill";
    pub const SKILL_LOAD_FAILED: &str = "Failed to load skill";

    /// Build a formatted "skill not found" error message.
    pub fn skill_not_found_error(name: &str) -> anyhow::Error {
        anyhow::anyhow!("Skill '{name}' not found")
    }
}

#[cfg(test)]
mod tests {
    use super::*;

    fn internal_unified_tool_name(suffix: &str) -> String {
        format!("unified_{suffix}")
    }

    #[test]
    fn test_agent_execution_message_helpers() {
        let planning_msg = agent_execution::planning_workflow_denial_message("write_file");
        assert!(agent_execution::is_planning_active_denial(&planning_msg));
        assert!(planning_msg.contains("blocked during planning"));
        assert!(planning_msg.contains("cargo check"));
        assert!(planning_msg.contains("exec_command"));
        assert!(planning_msg.contains("apply_patch"));
        assert!(!planning_msg.contains(&internal_unified_tool_name("file")));
        assert!(!planning_msg.contains(&internal_unified_tool_name("exec")));
        assert!(!planning_msg.contains(&internal_unified_tool_name("search")));
        assert!(!planning_msg.contains(&format!("/{}", "mode")));
        assert!(!planning_msg.contains("DO NOT retry this tool or use /plan off"));

        let loop_msg = agent_execution::loop_detection_block_message("read_file", 3, Some("base error"));
        assert!(loop_msg.starts_with(agent_execution::LOOP_DETECTION_PREFIX));
        assert!(loop_msg.contains(agent_execution::LOOP_RETRY_BLOCKED_LINE));
        assert!(loop_msg.contains("Original error: base error"));
        assert!(agent_execution::is_loop_detection_block_message(&loop_msg));
    }

    #[test]
    fn loop_detection_classification_ignores_prose_mentions() {
        use agent_execution::is_loop_detection_block_message;

        let generated = agent_execution::loop_detection_block_message("mcp::fs::read", 12, None);
        assert!(is_loop_detection_block_message(&generated));

        for message in [
            "warning: loop detection disabled for this target",
            "Loop detection is off; running tests",
            "stderr: Loop detection: Tool 'x' has been called 3 times with identical parameters and is now blocked.",
            "Loop detection: Tool 'x' has been called many times with identical parameters and is now blocked.",
            "Loop detection: Tool '' has been called 3 times with identical parameters and is now blocked.",
            "LOOP DETECTION: Tool 'x' has been called 3 times with identical parameters and is now blocked.",
        ] {
            assert!(!is_loop_detection_block_message(message), "{message:?}");
        }
    }
}