support env_logger / RUST_LOG (#7142)

3 files changed, 54 insertions, 33 deletions

diff --git a/cli/Cargo.toml b/cli/Cargo.toml
index 74694c165..bcd73cfc0 100644
--- a/cli/Cargo.toml
+++ b/cli/Cargo.toml
@@ -50,6 +50,7 @@ jsonc-parser = "0.14.0"
 lazy_static = "1.4.0"
 libc = "0.2.74"
 log = "0.4.11"
+env_logger = "0.7.1"
 notify = "5.0.0-pre.3"
 rand = "0.7.3"
 regex = "1.3.9"
diff --git a/cli/main.rs b/cli/main.rs
index d6b74d8a2..574ba9ed2 100644
--- a/cli/main.rs
+++ b/cli/main.rs
@@ -91,8 +91,6 @@ use flags::Flags;
 use futures::future::FutureExt;
 use futures::Future;
 use log::Level;
-use log::Metadata;
-use log::Record;
 use state::exit_unstable;
 use std::env;
 use std::io::Read;
@@ -104,35 +102,6 @@ use std::sync::Arc;
 use upgrade::upgrade_command;
 use url::Url;
 
-static LOGGER: Logger = Logger;
-
-// TODO(ry) Switch to env_logger or other standard crate.
-struct Logger;
-
-impl log::Log for Logger {
-  fn enabled(&self, metadata: &Metadata) -> bool {
-    metadata.level() <= log::max_level()
-  }
-
-  fn log(&self, record: &Record) {
-    if self.enabled(record.metadata()) {
-      let mut target = record.target().to_string();
-
-      if let Some(line_no) = record.line() {
-        target.push_str(":");
-        target.push_str(&line_no.to_string());
-      }
-
-      if record.level() >= Level::Info {
-        eprintln!("{}", record.args());
-      } else {
-        eprintln!("{} RS - {} - {}", record.level(), target, record.args());
-      }
-    }
-  }
-  fn flush(&self) {}
-}
-
 fn write_to_stdout_ignore_sigpipe(bytes: &[u8]) -> Result<(), std::io::Error> {
   use std::io::ErrorKind;
 
@@ -705,7 +674,6 @@ pub fn main() {
   #[cfg(windows)]
   colors::enable_ansi(); // For Windows 10
 
-  log::set_logger(&LOGGER).unwrap();
   let args: Vec<String> = env::args().collect();
   let flags = flags::flags_from_vec(args);
 
@@ -737,7 +705,29 @@ pub fn main() {
     Some(level) => level,
     None => Level::Info, // Default log level
   };
-  log::set_max_level(log_level.to_level_filter());
+  env_logger::Builder::from_env(
+    env_logger::Env::default()
+      .default_filter_or(log_level.to_level_filter().to_string()),
+  )
+  .format(|buf, record| {
+    let mut target = record.target().to_string();
+    if let Some(line_no) = record.line() {
+      target.push_str(":");
+      target.push_str(&line_no.to_string());
+    }
+    if record.level() >= Level::Info {
+      writeln!(buf, "{}", record.args())
+    } else {
+      writeln!(
+        buf,
+        "{} RS - {} - {}",
+        record.level(),
+        target,
+        record.args()
+      )
+    }
+  })
+  .init();
 
   let fut = match flags.clone().subcommand {
     DenoSubcommand::Bundle {
diff --git a/cli/tests/integration_tests.rs b/cli/tests/integration_tests.rs
index b8be7262d..08c68a9ae 100644
--- a/cli/tests/integration_tests.rs
+++ b/cli/tests/integration_tests.rs
@@ -3349,3 +3349,33 @@ fn should_not_panic_on_undefined_deno_dir_and_home_environment_variables() {
     .unwrap();
   assert!(output.status.success());
 }
+
+#[test]
+fn rust_log() {
+  // Without RUST_LOG the stderr is empty.
+  let output = util::deno_cmd()
+    .current_dir(util::root_path())
+    .arg("run")
+    .arg("cli/tests/001_hello.js")
+    .stderr(std::process::Stdio::piped())
+    .spawn()
+    .unwrap()
+    .wait_with_output()
+    .unwrap();
+  assert!(output.status.success());
+  assert!(output.stderr.is_empty());
+
+  // With RUST_LOG the stderr is not empty.
+  let output = util::deno_cmd()
+    .current_dir(util::root_path())
+    .arg("run")
+    .arg("cli/tests/001_hello.js")
+    .env("RUST_LOG", "debug")
+    .stderr(std::process::Stdio::piped())
+    .spawn()
+    .unwrap()
+    .wait_with_output()
+    .unwrap();
+  assert!(output.status.success());
+  assert!(!output.stderr.is_empty());
+}