Added log custom command & exported log levels (#9055)

# Description
- Log levels are now exported members of `std log`, e.g. `std log
CRITICAL_LEVEL`
- Added `std log custom` command that allows to declare custom message
format (actual message replaces `%MSG%` in the template) with
user-defined log level.


# User-Facing Changes
New possibilities included in description

# Tests + Formatting
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crates/nu-std/lib/log.nu

@@ -1,24 +1,49 @@
-def CRITICAL_LEVEL [] { 50 }
+export def "log CRITICAL_LEVEL" [] { 50 }
-def ERROR_LEVEL    [] { 40 }
+export def "log ERROR_LEVEL"    [] { 40 }
-def WARNING_LEVEL  [] { 30 }
+export def "log WARNING_LEVEL"  [] { 30 }
-def INFO_LEVEL     [] { 20 }
+export def "log INFO_LEVEL"     [] { 20 }
-def DEBUG_LEVEL    [] { 10 }
+export def "log DEBUG_LEVEL"    [] { 10 }
+
+export def "log CRITICAL_LEVEL_PREFIX" [] { "CRT" }
+export def "log ERROR_LEVEL_PREFIX"    [] { "ERR" }
+export def "log WARNING_LEVEL_PREFIX"  [] { "WRN" }
+export def "log INFO_LEVEL_PREFIX"     [] { "INF" }
+export def "log DEBUG_LEVEL_PREFIX"    [] { "DBG" }   
 
 def parse-string-level [level: string] {
     (
-        if $level == "CRITICAL" { (CRITICAL_LEVEL)}
+        if ($level in [(log CRITICAL_LEVEL_PREFIX) "CRIT" "CRITICAL"]) {
-        else if $level == "CRIT" { (CRITICAL_LEVEL)}
+            log CRITICAL_LEVEL
-        else if $level == "ERROR" { (ERROR_LEVEL) }
+        } else if ($level in [(log ERROR_LEVEL_PREFIX) "ERROR" ]) {
-        else if $level == "WARNING" { (WARNING_LEVEL) }
+            log ERROR_LEVEL
-        else if $level == "WARN" { (WARNING_LEVEL) }
+        } else if ($level in [(log WARNING_LEVEL_PREFIX) "WARN" "WARNING"]) {
-        else if $level == "INFO" { (INFO_LEVEL) }
+            log WARNING_LEVEL
-        else if $level == "DEBUG" { (DEBUG_LEVEL) }
+        } else if ($level in [(log DEBUG_LEVEL_PREFIX) "DEBUG"]) {
-        else { (INFO_LEVEL) }
+            log DEBUG_LEVEL
+        } else {
+            log INFO_LEVEL
+        }
+    )
+}
+
+def parse-int-level [level: int] {
+    (
+        if ($level >= (log CRITICAL_LEVEL)) {
+            log CRITICAL_LEVEL_PREFIX
+        } else if ($level >= (log ERROR_LEVEL)) {
+            log ERROR_LEVEL_PREFIX
+        } else if ($level >= (log WARNING_LEVEL)) {
+            log WARNING_LEVEL_PREFIX
+        } else if ($level >= (log INFO_LEVEL)) {
+            log INFO_LEVEL_PREFIX
+        } else {
+            log DEBUG_LEVEL_PREFIX
+        }
     )
 }
 
 def current-log-level [] {
-    let env_level = ($env | get -i NU_LOG_LEVEL | default (INFO_LEVEL))
+    let env_level = ($env | get -i NU_LOG_LEVEL | default (log INFO_LEVEL))
 
     try {
         ($env_level | into int)
@@ -33,31 +58,50 @@ def now [] {
 
 # Log critical message
 export def "log critical" [message: string] {
-    if (current-log-level) > (CRITICAL_LEVEL) { return }
+    if (current-log-level) > (log CRITICAL_LEVEL) { return }
 
-    print --stderr $"(ansi red_bold)CRT|(now)|($message)(ansi reset)"
+    print --stderr $"(ansi red_bold)(log CRITICAL_LEVEL_PREFIX)|(now)|($message)(ansi reset)"
 }
 # Log error message
 export def "log error" [message: string] {
-    if (current-log-level) > (ERROR_LEVEL) { return }
+    if (current-log-level) > (log ERROR_LEVEL) { return }
 
-    print --stderr $"(ansi red)ERR|(now)|($message)(ansi reset)"
+    print --stderr $"(ansi red)(log ERROR_LEVEL_PREFIX)|(now)|($message)(ansi reset)"
 }
 # Log warning message
 export def "log warning" [message: string] {
-    if (current-log-level) > (WARNING_LEVEL) { return }
+    if (current-log-level) > (log WARNING_LEVEL) { return }
 
-    print --stderr $"(ansi yellow)WRN|(now)|($message)(ansi reset)"
+    print --stderr $"(ansi yellow)(log WARNING_LEVEL_PREFIX)|(now)|($message)(ansi reset)"
 }
 # Log info message
 export def "log info" [message: string] {
-    if (current-log-level) > (INFO_LEVEL) { return }
+    if (current-log-level) > (log INFO_LEVEL) { return }
 
-    print --stderr $"(ansi default)INF|(now)|($message)(ansi reset)"
+    print --stderr $"(ansi default)(log INFO_LEVEL_PREFIX)|(now)|($message)(ansi reset)"
 }
 # Log debug message
 export def "log debug" [message: string] {
-    if (current-log-level) > (DEBUG_LEVEL) { return }
+    if (current-log-level) > (log DEBUG_LEVEL) { return }
 
-    print --stderr $"(ansi default_dimmed)DBG|(now)|($message)(ansi reset)"
+    print --stderr $"(ansi default_dimmed)(log DEBUG_LEVEL_PREFIX)|(now)|($message)(ansi reset)"
+}
+
+# Log with custom message format and verbosity level
+# 
+# Format reference:
+#   > %MSG% will be replaced by $message
+#   > %DATE% will be replaced by the timestamp of log in standard Nushell's log format: "%Y-%m-%dT%H:%M:%S%.3f"
+#   > %LEVEL% will be replaced by the standard Nushell's log verbosity prefixes, e.g. "CRT"
+#
+# Examples:
+#   > std log custom "my message" $"(ansi yellow)[%LEVEL%]MY MESSAGE: %MSG% [%DATE%](ansi reset)" (std log WARNING_LEVEL) 
+export def "log custom" [
+    message: string, # Message inserted into the log template
+    format: string, # A string to be printed into stderr. 
+    log_level: int # Log's verbosity level
+    ] {
+    if (current-log-level) > ($log_level) { return }
+
+    print --stderr ($format | str replace "%MSG%" $message | str replace "%DATE%" (now) | str replace "%LEVEL%" (parse-int-level $log_level | into string))
 }

crates/nu-std/tests/test_logger.nu

@@ -36,3 +36,41 @@ export def test_debug [] {
     assert no message INFO debug 
     assert message DEBUG debug DBG
 }
+
+
+def "run custom" [system_level, format, message_level] {
+    do {
+        ^$nu.current-exe -c $'use std; NU_LOG_LEVEL=($system_level) std log custom "test message" "($format)" ($message_level)' 
+    } | complete | get -i stderr
+}
+
+def "assert custom message" [system_level, format, message_level] {
+    let output = (run custom $system_level $format $message_level)
+    assert equal ($output | str trim -r) ($format | str replace "%MSG%" "test message")
+}
+
+def "assert custom message contains" [system_level, format, message_level, tested_str] {
+    let output = (run custom $system_level $format $message_level)
+    assert ($output | str contains  $tested_str)
+    assert ($output | str contains "test message")
+}
+
+def "assert custom message not contains" [system_level, format, message_level, tested_str] {
+    let output = (run custom $system_level $format $message_level)
+    assert (not ($output | str contains  $tested_str))
+    assert ($output | str contains "test message")
+}
+
+def "assert no custom message" [system_level, format, message_level] {
+    let output = (run custom $system_level $format $message_level)
+    assert equal ($output | str trim -r) ""
+}
+
+export def test_custom [] {
+    assert no custom message (log ERROR_LEVEL) "%MSG%" (log DEBUG_LEVEL)
+    assert custom message (log DEBUG_LEVEL) "%MSG%" (log INFO_LEVEL)
+    assert custom message (log WARNING_LEVEL) $"my_msg: %MSG%" (log CRITICAL_LEVEL)
+
+    assert custom message contains (log DEBUG_LEVEL) $"(ansi yellow)[%LEVEL%]MY MESSAGE: %MSG% [%DATE%](ansi reset)" (log WARNING_LEVEL) (log WARNING_LEVEL_PREFIX)
+    assert custom message not contains (log DEBUG_LEVEL) $"(ansi yellow)MY MESSAGE: %MSG% [%DATE%](ansi reset)" (log WARNING_LEVEL) (log WARNING_LEVEL_PREFIX)
+}