captains_log/
env.rs

1use log::Level;
2use std::path::{Path, PathBuf};
3use std::str::FromStr;
4
5#[doc(hidden)]
6#[macro_export(local_inner_macros)]
7macro_rules! impl_from_env {
8    ($type: tt) => {
9        impl<'a> Into<$type> for EnvVarDefault<'a, $type> {
10            #[inline]
11            fn into(self) -> $type {
12                if let Ok(v) = std::env::var(&self.name) {
13                    match $type::from_str(&v) {
14                        Ok(r) => return r,
15                        Err(_) => {
16                            std::eprintln!(
17                                "env {}={} is not valid, set to {:?}",
18                                self.name,
19                                v,
20                                self.default
21                            );
22                        }
23                    }
24                }
25                return self.default;
26            }
27        }
28    };
29}
30
31pub struct EnvVarDefault<'a, T> {
32    pub(crate) name: &'a str,
33    pub(crate) default: T,
34}
35
36/// To config some logger setting with env.
37///
38/// Read value from environment, and set with default if not exists.
39///
40/// NOTE: the arguments to load from env_or() must support owned values.
41///
42/// Example:
43///
44/// ```rust
45/// use captains_log::*;
46/// let _level: log::Level = env_or("LOG_LEVEL", Level::Info).into();
47/// let _file_path: String = env_or("LOG_FILE", "/tmp/test.log").into();
48/// let _console: ConsoleTarget = env_or("LOG_CONSOLE", ConsoleTarget::Stdout).into();
49/// ```
50pub fn env_or<'a, T>(name: &'a str, default: T) -> EnvVarDefault<'a, T> {
51    EnvVarDefault { name, default }
52}
53
54impl<'a> Into<String> for EnvVarDefault<'a, &'a str> {
55    fn into(self) -> String {
56        if let Ok(v) = std::env::var(&self.name) {
57            return v;
58        }
59        return self.default.to_string();
60    }
61}
62
63impl<'a, P: AsRef<Path>> Into<PathBuf> for EnvVarDefault<'a, P> {
64    fn into(self) -> PathBuf {
65        if let Some(v) = std::env::var_os(&self.name) {
66            if v.len() > 0 {
67                return PathBuf::from(v);
68            }
69        }
70        return self.default.as_ref().to_path_buf();
71    }
72}
73
74crate::impl_from_env!(Level);
75
76#[cfg(test)]
77mod tests {
78    use super::*;
79    use crate::recipe;
80    use crate::*;
81
82    #[test]
83    fn test_env_config() {
84        // test log level
85        unsafe { std::env::set_var("LEVEL", "warn") };
86        let level: Level = env_or("LEVEL", Level::Debug).into();
87        assert_eq!(level, Level::Warn);
88        unsafe { std::env::set_var("LEVEL", "WARN") };
89        let level: Level = env_or("LEVEL", Level::Debug).into();
90        assert_eq!(level, Level::Warn);
91
92        assert_eq!(ConsoleTarget::from_str("Stdout").unwrap(), ConsoleTarget::Stdout);
93        assert_eq!(ConsoleTarget::from_str("StdERR").unwrap(), ConsoleTarget::Stderr);
94        assert_eq!(ConsoleTarget::from_str("1").unwrap(), ConsoleTarget::Stdout);
95        assert_eq!(ConsoleTarget::from_str("2").unwrap(), ConsoleTarget::Stderr);
96        assert_eq!(ConsoleTarget::from_str("0").unwrap_err(), ());
97
98        // test console target
99        unsafe { std::env::set_var("CONSOLE", "stderr") };
100        let target: ConsoleTarget = env_or("CONSOLE", ConsoleTarget::Stdout).into();
101        assert_eq!(target, ConsoleTarget::Stderr);
102        unsafe { std::env::set_var("CONSOLE", "") };
103        let target: ConsoleTarget = env_or("CONSOLE", ConsoleTarget::Stdout).into();
104        assert_eq!(target, ConsoleTarget::Stdout);
105
106        // test path
107        unsafe { std::env::set_var("LOG_PATH", "/tmp/test.log") };
108        let path: PathBuf = env_or("LOG_PATH", "/tmp/other.log").into();
109        assert_eq!(path, Path::new("/tmp/test.log").to_path_buf());
110
111        unsafe { std::env::set_var("LOG_PATH", "") };
112        let path: PathBuf = env_or("LOG_PATH", "/tmp/other.log").into();
113        assert_eq!(path, Path::new("/tmp/other.log").to_path_buf());
114
115        let _builder = recipe::raw_file_logger(env_or("LOG_PATH", "/tmp/other.log"), Level::Info);
116        let _builder =
117            recipe::raw_file_logger(env_or("LOG_PATH", "/tmp/other.log".to_string()), Level::Info);
118    }
119}
captains_log/env.rs

captains_log/
env.rs
