From fcee4265c605c09062d7cb2984c2776e8b8f0247 Mon Sep 17 00:00:00 2001
From: tokiedokie <thetokiedokie@gmail.com>
Date: Fri, 4 Sep 2020 05:16:49 +0900
Subject: [PATCH] support env_logger / RUST_LOG (#7142)

---
 Cargo.lock                     | 23 ++++++++++++++
 cli/Cargo.toml                 |  1 +
 cli/main.rs                    | 56 ++++++++++++++--------------------
 cli/tests/integration_tests.rs | 30 ++++++++++++++++++
 4 files changed, 77 insertions(+), 33 deletions(-)

diff --git a/Cargo.lock b/Cargo.lock
index d51e476bf0..0ff3e3a33e 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -388,6 +388,7 @@ dependencies = [
  "dlopen",
  "dprint-plugin-typescript",
  "encoding_rs",
+ "env_logger",
  "filetime",
  "futures",
  "fwdansi",
@@ -586,6 +587,19 @@ dependencies = [
  "syn 1.0.36",
 ]
 
+[[package]]
+name = "env_logger"
+version = "0.7.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "44533bbbb3bb3c1fa17d9f2e4e38bbbaf8396ba82193c4cb1b6445d711445d36"
+dependencies = [
+ "atty",
+ "humantime",
+ "log 0.4.11",
+ "regex",
+ "termcolor",
+]
+
 [[package]]
 name = "errno"
 version = "0.1.8"
@@ -909,6 +923,15 @@ version = "1.3.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "cd179ae861f0c2e53da70d892f5f3029f9594be0c41dc5269cd371691b1dc2f9"
 
+[[package]]
+name = "humantime"
+version = "1.3.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "df004cfca50ef23c36850aaaa59ad52cc70d0e90243c3c7737a4dd32dc7a3c4f"
+dependencies = [
+ "quick-error",
+]
+
 [[package]]
 name = "hyper"
 version = "0.13.6"
diff --git a/cli/Cargo.toml b/cli/Cargo.toml
index 74694c1657..bcd73cfc06 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 d6b74d8a2a..574ba9ed2f 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 b8be7262d2..08c68a9ae2 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());
+}