use std::borrow::Cow;
use std::env;
use std::error::Error;
pub fn extract_database_url(url: &str) -> Result<Cow<str>, String> {
if url.starts_with("dotenv:") {
try!(load_dotenv_file());
extract_database_url(&url[3..])
} else if url.starts_with("env:") {
let var_name = &url[4..];
env::var(var_name)
.map(Cow::Owned)
.map_err(|e| {
format!("Failed to load environment variable {}: {}",
var_name, e.description())
})
} else {
Ok(Cow::Borrowed(url))
}
}
#[cfg(feature = "dotenv")]
fn load_dotenv_file() -> Result<(), String> {
use dotenv::dotenv;
dotenv().ok();
Ok(())
}
#[cfg(not(feature = "dotenv"))]
fn load_dotenv_file() -> Result<(), String> {
Err(String::from("diesel_codegen must be compiled with the \"dotenv\" \
feature to correctly interpret strings starting with `dotenv:`"))
}
#[test]
fn extract_database_url_returns_the_given_string() {
assert_eq!("foo", extract_database_url("foo").unwrap());
assert_eq!("bar", extract_database_url("bar").unwrap());
}
#[test]
fn extract_database_url_returns_env_vars() {
env::set_var("lolvar", "lololol");
env::set_var("trolvar", "trolololol");
assert_eq!("lololol", extract_database_url("env:lolvar").unwrap());
assert_eq!("trolololol", extract_database_url("env:trolvar").unwrap());
}
#[test]
fn extract_database_url_errors_if_env_var_is_unset() {
env::remove_var("selfdestructvar");
assert!(extract_database_url("env:selfdestructvar").is_err());
}