feat(pact_ffi): Allow turn off log

rust/pact_ffi/src/lib.rs

@@ -12,7 +12,7 @@ use std::str::FromStr;
 use lazy_static::lazy_static;
 use libc::c_char;
 use tracing::{debug, error, info, trace, warn};
-use tracing_core::Level;
+use tracing_core::{Level, LevelFilter};
 use tracing_log::AsLog;
 use tracing_subscriber::FmtSubscriber;
 
@@ -85,12 +85,14 @@ pub unsafe extern fn pactffi_init(log_env_var: *const c_char) {
 /// Initialises logging, and sets the log level explicitly. This function should only be called
 /// once, as it tries to install a global tracing subscriber.
 ///
+/// * `log_level` - String (case-insensitive). One of TRACE, DEBUG, INFO, WARN, ERROR, NONE/OFF
+///
 /// # Safety
 ///
 /// Exported functions are inherently unsafe.
 #[no_mangle]
 pub unsafe extern "C" fn pactffi_init_with_log_level(level: *const c_char) {
-  let log_level = log_level_from_c_char(level);
+  let log_level = log_level_filter_from_c_char(level);
   let subscriber = FmtSubscriber::builder()
     .with_max_level(log_level)
     .with_thread_names(true)
@@ -160,6 +162,18 @@ unsafe fn log_level_from_c_char(log_level: *const c_char) -> Level {
   }
 }
 
+unsafe fn log_level_filter_from_c_char(log_level: *const c_char) -> LevelFilter {
+  if !log_level.is_null() {
+    let level = convert_cstr("log_level", log_level).unwrap_or("INFO");
+    match level.to_lowercase().as_str() {
+      "none" => LevelFilter::OFF,
+      _ => LevelFilter::from_str(level).unwrap_or(LevelFilter::INFO)
+    }
+  } else {
+    LevelFilter::INFO
+  }
+}
+
 fn convert_cstr(name: &str, value: *const c_char) -> Option<&str> {
     unsafe {
         if value.is_null() {
@@ -316,3 +330,36 @@ impl MismatchesIterator {
         idx
     }
 }
+
+#[cfg(test)]
+mod tests {
+  use std::ffi::CString;
+
+  use expectest::prelude::*;
+  use rstest::rstest;
+
+  use super::log_level_filter_from_c_char;
+  use tracing_core::LevelFilter;
+
+  #[rstest]
+  #[case("trace", LevelFilter::TRACE)]
+  #[case("TRACE", LevelFilter::TRACE)]
+  #[case("debug", LevelFilter::DEBUG)]
+  #[case("DEBUG", LevelFilter::DEBUG)]
+  #[case("info", LevelFilter::INFO)]
+  #[case("INFO", LevelFilter::INFO)]
+  #[case("warn", LevelFilter::WARN)]
+  #[case("WARN", LevelFilter::WARN)]
+  #[case("error", LevelFilter::ERROR)]
+  #[case("ERROR", LevelFilter::ERROR)]
+  #[case("off", LevelFilter::OFF)]
+  #[case("OFF", LevelFilter::OFF)]
+  #[case("none", LevelFilter::OFF)]
+  #[case("NONE", LevelFilter::OFF)]
+  #[case("invalid", LevelFilter::INFO)]
+  fn log_level_filter_from_c_char_test(#[case] text: String, #[case] level: LevelFilter) {
+    let value = CString::new(text).unwrap();
+    let result = unsafe { log_level_filter_from_c_char(value.as_ptr()) };
+    expect!(result).to(be_equal_to(level));
+  }
+}