Enum LogFormat

Source

pub enum LogFormat {
    Text,
    Json,
}

Expand description

Diagnostic log output format.

Selects whether mcp-execution-cli and mcp-execution-server emit human-readable text logs or structured JSON logs. Independent of OutputFormat, which controls command result output, not diagnostic logging.

§Examples

use mcp_execution_core::cli::LogFormat;

let format = LogFormat::Json;
assert_eq!(format.as_str(), "json");

let format: LogFormat = "TEXT".parse().unwrap();
assert_eq!(format, LogFormat::Text);

Variants§

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Text

Human-readable text logs.

§

Json

Structured JSON logs, one object per line.

Implementations§

Source §

impl LogFormat

Source

pub const fn as_str(&self) -> &'static str

Returns the string representation of the format.

§Examples

use mcp_execution_core::cli::LogFormat;

assert_eq!(LogFormat::Text.as_str(), "text");
assert_eq!(LogFormat::Json.as_str(), "json");

Source

pub fn resolve(flag: Option<Self>, env_value: Option<&str>) -> Self

Resolves the effective log format from an optional CLI flag value and an optional raw environment variable value.

Precedence: flag wins unconditionally when set — env_value is not even inspected, so a malformed environment value has no effect on the result once the flag has already resolved the format. Otherwise the env value is parsed via LogFormat::parse_env, which treats an empty/whitespace-only or unrecognized value alike as “no override” and falls back to LogFormat::default.

Returns only the resolved format, not the rejected raw value: neither production caller logs it (a raw MCP_EXECUTION_LOG_FORMAT value is untrusted external input, and echoing it — even truncated — would open a log-injection vector), so carrying it through this return type would be a capability with no real consumer. A caller that needs to know whether the env value was invalid specifically (as opposed to merely absent), e.g. to decide whether to log a warning, calls LogFormat::is_invalid_env_value separately.

Deliberately free of std::env access itself: callers pass std::env::var(LOG_FORMAT_ENV_VAR).ok() in, which keeps precedence and fallback behavior testable without mutating process environment state. One accepted consequence of that call shape: a non-UTF-8 MCP_EXECUTION_LOG_FORMAT value folds to Err(VarError::NotUnicode(_)), hence None here, so it is silently treated as unset rather than invalid — unlike a valid-UTF-8 but unrecognized value (e.g. "xml"), which LogFormat::is_invalid_env_value does flag for a caller to warn about. Not worth switching callers to std::env::var_os to close this gap: a non-UTF-8 value is exceedingly unlikely for a variable whose only valid values are ASCII, and the failure mode (no warning, falls back to the same default a bad value would) is identical either way.

§Examples

use mcp_execution_core::cli::LogFormat;

// The flag wins even over a valid env value.
assert_eq!(LogFormat::resolve(Some(LogFormat::Json), Some("text")), LogFormat::Json);

// No flag: a valid env value is used, case-insensitively.
assert_eq!(LogFormat::resolve(None, Some("JSON")), LogFormat::Json);

// No flag, unrecognized env value: falls back to the default (`Text`).
assert_eq!(LogFormat::resolve(None, Some("xml")), LogFormat::Text);

Source

pub fn parse_env(raw: &str) -> Option<Self>

Parses a raw MCP_EXECUTION_LOG_FORMAT environment-variable value.

Returns None uniformly for an empty/whitespace-only value and for one that doesn’t match text/json (case-insensitive) — both are “no override” as far as resolve is concerned. Use LogFormat::is_invalid_env_value when the two None cases need to be told apart (e.g. to decide whether a caller should warn about a rejected value).

§Examples

use mcp_execution_core::cli::LogFormat;

assert_eq!(LogFormat::parse_env("json"), Some(LogFormat::Json));
assert_eq!(LogFormat::parse_env("JSON"), Some(LogFormat::Json));
assert_eq!(LogFormat::parse_env(""), None);
assert_eq!(LogFormat::parse_env("   "), None);
assert_eq!(LogFormat::parse_env("xml"), None);

Source

pub fn is_invalid_env_value(raw: &str) -> bool

True when raw is a genuinely invalid MCP_EXECUTION_LOG_FORMAT value — non-empty and not parseable via LogFormat::parse_env — as opposed to an empty/whitespace-only value, which is merely “unset” and not worth warning about. Lets a caller decide whether to emit a warning without re-implementing parse_env’s own emptiness check.

§Examples

use mcp_execution_core::cli::LogFormat;

assert!(LogFormat::is_invalid_env_value("xml"));
assert!(!LogFormat::is_invalid_env_value("json"));
assert!(!LogFormat::is_invalid_env_value(""));
assert!(!LogFormat::is_invalid_env_value("   "));