fix(log): inconsistent webview log target (#2021)

* Fix very inconsistent webview log target

* Add change file

* It's log-plugin not log

* Lower rust version requirement

* Use the third line instead of second

.changes/fix-inconsistent-webview-log-target.md

@@ -0,0 +1,6 @@
+---
+'log-plugin': 'patch'
+'log-js': 'patch'
+---
+
+Make webview log target more consistent that it always starts with `webview`

plugins/log/guest-js/index.ts

@@ -44,24 +44,78 @@ enum LogLevel {
   Error
 }
 
+function getCallerLocation(stack?: string) {
+  if (!stack) {
+    return
+  }
+
+  if (stack.startsWith('Error')) {
+    // Assume it's Chromium V8
+    //
+    // Error
+    //     at baz (filename.js:10:15)
+    //     at bar (filename.js:6:3)
+    //     at foo (filename.js:2:3)
+    //     at filename.js:13:1
+
+    const lines = stack.split('\n')
+    // Find the third line (caller's caller of the current location)
+    const callerLine = lines[3].trim()
+
+    const regex =
+      /at\s+(?<functionName>.*?)\s+\((?<fileName>.*?):(?<lineNumber>\d+):(?<columnNumber>\d+)\)/
+    const match = callerLine.match(regex)
+
+    if (match) {
+      const { functionName, fileName, lineNumber, columnNumber } =
+        match.groups as {
+          functionName: string
+          fileName: string
+          lineNumber: string
+          columnNumber: string
+        }
+      return `${functionName}@${fileName}:${lineNumber}:${columnNumber}`
+    } else {
+      // Handle cases where the regex does not match (e.g., last line without function name)
+      const regexNoFunction =
+        /at\s+(?<fileName>.*?):(?<lineNumber>\d+):(?<columnNumber>\d+)/
+      const matchNoFunction = callerLine.match(regexNoFunction)
+      if (matchNoFunction) {
+        const { fileName, lineNumber, columnNumber } =
+          matchNoFunction.groups as {
+            fileName: string
+            lineNumber: string
+            columnNumber: string
+          }
+        return `<anonymous>@${fileName}:${lineNumber}:${columnNumber}`
+      }
+    }
+  } else {
+    // Assume it's Webkit JavaScriptCore, example:
+    //
+    // [email protected]:10:24
+    // [email protected]:6:6
+    // [email protected]:2:6
+    // global [email protected]:13:4
+
+    const traces = stack.split('\n').map((line) => line.split('@'))
+    const filtered = traces.filter(([name, location]) => {
+      return name.length > 0 && location !== '[native code]'
+    })
+    // Find the third line (caller's caller of the current location)
+    return filtered[2].filter((v) => v.length > 0).join('@')
+  }
+}
+
 async function log(
   level: LogLevel,
   message: string,
   options?: LogOptions
 ): Promise<void> {
-  const traces = new Error().stack?.split('\n').map((line) => line.split('@'))
-
-  const filtered = traces?.filter(([name, location]) => {
-    return name.length > 0 && location !== '[native code]'
-  })
+  const location = getCallerLocation(new Error().stack)
 
   const { file, line, keyValues } = options ?? {}
 
-  let location = filtered?.[0]?.filter((v) => v.length > 0).join('@')
-  if (location === 'Error') {
-    location = 'webview::unknown'
-  }
-
   await invoke('plugin:log|log', {
     level,
     message,

plugins/log/src/lib.rs

@@ -33,7 +33,7 @@ use tauri::{AppHandle, Emitter};
 pub use fern;
 use time::OffsetDateTime;
 
-pub const WEBVIEW_TARGET: &str = "Webview";
+pub const WEBVIEW_TARGET: &str = "webview";
 
 #[cfg(target_os = "ios")]
 mod ios {
@@ -230,22 +230,16 @@ fn log(
     line: Option<u32>,
     key_values: Option<HashMap<String, String>>,
 ) {
-    let location = location.unwrap_or("webview");
-
     let level = log::Level::from(level);
 
-    let metadata = log::MetadataBuilder::new()
-        .level(level)
-        .target(WEBVIEW_TARGET)
-        .build();
+    let target = if let Some(location) = location {
+        format!("{WEBVIEW_TARGET}:{location}")
+    } else {
+        WEBVIEW_TARGET.to_string()
+    };
 
     let mut builder = RecordBuilder::new();
-    builder
-        .level(level)
-        .metadata(metadata)
-        .target(location)
-        .file(file)
-        .line(line);
+    builder.level(level).target(&target).file(file).line(line);
 
     let key_values = key_values.unwrap_or_default();
     let mut kv = HashMap::new();
@@ -380,8 +374,8 @@ impl Builder {
     ///     .clear_targets()
     ///     .targets([
     ///         Target::new(TargetKind::Webview),
-    ///         Target::new(TargetKind::LogDir { file_name: Some("webview".into()) }).filter(|metadata| metadata.target() == WEBVIEW_TARGET),
-    ///         Target::new(TargetKind::LogDir { file_name: Some("rust".into()) }).filter(|metadata| metadata.target() != WEBVIEW_TARGET),
+    ///         Target::new(TargetKind::LogDir { file_name: Some("webview".into()) }).filter(|metadata| metadata.target().starts_with(WEBVIEW_TARGET)),
+    ///         Target::new(TargetKind::LogDir { file_name: Some("rust".into()) }).filter(|metadata| !metadata.target().starts_with(WEBVIEW_TARGET)),
     ///     ]);
     /// ```
     pub fn targets(mut self, targets: impl IntoIterator<Item = Target>) -> Self {