fix(mapping): Parse Compose mappings with flexible indentation (#93)

Parse Compose mappings with flexible indentation

`ComposeStackTrace -> $$compose:` sections generated by recent Android
builds use two-space member indentation. The Compose compiler emits
those entries with two leading spaces in
https://github.com/JetBrains/kotlin/blob/effb244358aec74b7fa752d70a1055b4ea2f3e57/plugins/compose/group-mapping/src/main/kotlin/androidx/compose/compiler/mapping/ComposeMapping.kt#L54,
which does not follow the ProGuard spec for member lines. As a result,
those entries were dropped during cache generation, leaving
symbolication able to remap `$$compose` to `ComposeStackTrace` but not
to the original methods.

I already filed https://issuetracker.google.com/issues/504284805, but we
still need to fix this on our side because there are existing broken
mappings in the wild that we need to support. This changes the parser to
accept indented member lines and adds focused mapper and cache
regressions for the raw Compose stacktrace shape.

Refs getsentry/sentry-android-gradle-plugin#1065

---------

Co-authored-by: Codex <noreply@openai.com>

Author: romtsn

src/mapping.rs

@@ -161,13 +161,7 @@ impl<'s> ProguardMapping<'s> {
     /// let valid = ProguardMapping::new(b"a -> b:\n    void method() -> b");
     /// assert_eq!(valid.is_valid(), true);
     ///
-    /// let invalid = ProguardMapping::new(
-    ///     br#"
-    /// # looks: like
-    /// a -> proguard:
-    ///   mapping but(is) -> not
-    /// "#,
-    /// );
+    /// let invalid = ProguardMapping::new(b"a -> proguard:\n  not a valid proguard member line");
     /// assert_eq!(invalid.is_valid(), false);
     /// ```
     pub fn is_valid(&self) -> bool {
@@ -505,7 +499,7 @@ fn parse_proguard_record(bytes: &[u8]) -> (Result<ProguardRecord<'_>, ParseError
         } else {
             parse_proguard_header(bytes)
         }
-    } else if bytes.starts_with(b"    ") {
+    } else if matches!(bytes.first(), Some(b' ' | b'\t')) {
         parse_proguard_field_or_method(bytes)
     } else {
         parse_proguard_class(bytes)
@@ -568,7 +562,7 @@ fn parse_proguard_field_or_method(
     // field line or method line:
     // `originalfieldtype originalfieldname -> obfuscatedfieldname`
     // `[startline:endline:]originalreturntype [originalclassname.]originalmethodname(originalargumenttype,...)[:originalstartline[:originalendline]] -> obfuscatedmethodname`
-    let bytes = parse_prefix(bytes, b"    ")?;
+    let bytes = bytes.trim_ascii_start();
 
     let (startline, bytes) = match parse_usize(bytes) {
         Ok((startline, bytes)) => (Some(startline), bytes),
@@ -1063,15 +1057,15 @@ mod tests {
     }
 
     #[test]
-    fn try_parse_field_insufficient_leading_spaces() {
-        // only 2 leading spaces instead of 4
+    fn try_parse_field_with_two_space_indentation() {
         let bytes = b"  android.app.Activity mActivity -> a";
         let parsed = ProguardRecord::try_parse(bytes);
         assert_eq!(
             parsed,
-            Err(ParseError {
-                line: bytes,
-                kind: ParseErrorKind::ParseError("line is not a valid proguard record"),
+            Ok(ProguardRecord::Field {
+                ty: "android.app.Activity",
+                original: "mActivity",
+                obfuscated: "a",
             }),
         );
     }
@@ -1145,9 +1139,10 @@ androidx.activity.OnBackPressedCallback
                     original: "mEnabled",
                     obfuscated: "a",
                 }),
-                Err(ParseError {
-                    line: b"  boolean mEnabled -> a\n",
-                    kind: ParseErrorKind::ParseError("line is not a valid proguard record"),
+                Ok(ProguardRecord::Field {
+                    ty: "boolean",
+                    original: "mEnabled",
+                    obfuscated: "a",
                 }),
                 Ok(ProguardRecord::Field {
                     ty: "java.util.ArrayDeque",

tests/retrace.rs

@@ -1,4 +1,4 @@
-use proguard::{ProguardMapper, StackFrame};
+use proguard::{ProguardCache, ProguardMapper, ProguardMapping, StackFrame};
 
 #[test]
 fn test_remap() {
@@ -130,3 +130,56 @@ fn test_remap_just_method() {
     let ambiguous = mapper.remap_method("a.b.c.d", "buttonClicked");
     assert_eq!(ambiguous, None);
 }
+
+#[test]
+fn test_remap_compose_stacktrace_group_keys() {
+    let mapping = r#"ComposeStackTrace -> $$compose:
+  1:1:androidx.compose.runtime.State androidx.compose.animation.core.AnimateAsStateKt.animateFloatAsState(float,androidx.compose.animation.core.AnimationSpec,float,java.lang.String,kotlin.jvm.functions.Function1,androidx.compose.runtime.Composer,int,int):71:71 -> m$1125598679
+  1:1:androidx.compose.runtime.State androidx.compose.animation.core.AnimateAsStateKt.animateFloatAsState(float,androidx.compose.animation.core.AnimationSpec,float,java.lang.String,kotlin.jvm.functions.Function1,androidx.compose.runtime.Composer,int,int):73:73 -> m$1125708605"#;
+    let mapper = ProguardMapper::from(mapping);
+
+    let mapped = mapper
+        .remap_stacktrace(
+            r#"androidx.compose.runtime.ComposeTraceException:
+    at $$compose.m$1125598679(SourceFile:1)
+    at $$compose.m$1125708605(SourceFile:1)"#,
+        )
+        .unwrap();
+
+    assert_eq!(
+        mapped.trim(),
+        r#"androidx.compose.runtime.ComposeTraceException:
+    at androidx.compose.animation.core.AnimateAsStateKt.animateFloatAsState(AnimateAsState.kt:71)
+    at androidx.compose.animation.core.AnimateAsStateKt.animateFloatAsState(AnimateAsState.kt:73)"#
+            .trim()
+    );
+}
+
+#[test]
+fn test_remap_compose_stacktrace_group_keys_cache() {
+    let mapping = ProguardMapping::new(
+        br#"ComposeStackTrace -> $$compose:
+  1:1:androidx.compose.runtime.State androidx.compose.animation.core.AnimateAsStateKt.animateFloatAsState(float,androidx.compose.animation.core.AnimationSpec,float,java.lang.String,kotlin.jvm.functions.Function1,androidx.compose.runtime.Composer,int,int):71:71 -> m$1125598679
+  1:1:androidx.compose.runtime.State androidx.compose.animation.core.AnimateAsStateKt.animateFloatAsState(float,androidx.compose.animation.core.AnimationSpec,float,java.lang.String,kotlin.jvm.functions.Function1,androidx.compose.runtime.Composer,int,int):73:73 -> m$1125708605"#,
+    );
+
+    let mut buf = Vec::new();
+    ProguardCache::write(&mapping, &mut buf).unwrap();
+    let cache = ProguardCache::parse(&buf).unwrap();
+
+    let mapped = cache
+        .remap_stacktrace(
+            r#"androidx.compose.runtime.ComposeTraceException:
+    at $$compose.m$1125598679(SourceFile:1)
+    at $$compose.m$1125708605(SourceFile:1)"#,
+        )
+        .unwrap();
+
+    assert_eq!(
+        mapped.trim(),
+        r#"androidx.compose.runtime.ComposeTraceException:
+    at androidx.compose.animation.core.AnimateAsStateKt.animateFloatAsState(AnimateAsState.kt:71)
+    at androidx.compose.animation.core.AnimateAsStateKt.animateFloatAsState(AnimateAsState.kt:73)"#
+            .trim()
+    );
+}