Don't treat CARGO_BIN_EXE_renamify as screaming snake case - preserve the lowercase text during replacement

Author: ndbroadbent

renamify-core/src/case_model.rs

@@ -82,19 +82,10 @@ pub fn detect_style(s: &str) -> Option<Style> {
         // Mixed case with underscores - treat as screaming snake if it starts with
         // uppercase identifier followed by underscore
         (true, false, false, false, true, true) => {
-            // Check if this looks like PREFIX_identifier pattern
-            // e.g., PRODUCTION_old_name, DEBUG_old_name
-            if let Some(first_underscore_pos) = s.find('_') {
-                let prefix = &s[..first_underscore_pos];
-                // If the prefix is all uppercase, treat as screaming snake
-                if !prefix.is_empty() && prefix.bytes().all(|b| b.is_ascii_uppercase()) {
-                    Some(Style::ScreamingSnake)
-                } else {
-                    Some(Style::Snake)
-                }
-            } else {
-                Some(Style::Snake)
-            }
+            // Mixed case with underscores - this is NOT a standard style
+            // Examples: CARGO_BIN_EXE_foobar, DEBUG_mode, PREFIX_camelCase
+            // These should preserve the exact case of the matched portion
+            None
         },
         (false, true, false, false, false, true) => Some(Style::Kebab),
         (false, true, false, false, true, false) => Some(Style::ScreamingTrain), // ALL-CAPS-WITH-HYPHENS

renamify-core/tests/mixed_case_prefix_test.rs

@@ -0,0 +1,120 @@
+use renamify_core::{apply_plan, scan_repository, ApplyOptions, PlanOptions};
+use std::fs;
+use tempfile::TempDir;
+
+#[test]
+fn test_mixed_case_prefix_replacement() {
+    // Test that when replacing lowercase identifiers that appear after uppercase prefixes,
+    // the replacement maintains the correct case (lowercase) rather than being coerced to uppercase
+
+    let temp_dir = TempDir::new().unwrap();
+    let test_file = temp_dir.path().join("test.rs");
+
+    // Test content with CARGO_BIN_EXE_ prefix followed by lowercase identifier
+    let content = r#"
+fn main() {
+    // This tests the CARGO_BIN_EXE_ pattern where the suffix should remain lowercase
+    let path = env!("CARGO_BIN_EXE_foobar");
+    let another = env!("CARGO_BIN_EXE_foobar");
+
+    // Also test with other mixed patterns
+    const PREFIX_foobar: &str = "test";
+    let DEBUG_foobar_enabled = true;
+
+    // Regular lowercase should still work
+    let foobar_config = "config";
+    let simple_foobar = "test";
+}
+"#;
+
+    fs::write(&test_file, content).unwrap();
+
+    // Search for "foobar" and replace with "baz_qux"
+    let mut plan = scan_repository(
+        temp_dir.path(),
+        "foobar",
+        "baz_qux",
+        &PlanOptions::default(),
+    )
+    .unwrap();
+
+    // Apply the plan
+    apply_plan(&mut plan, &ApplyOptions::default()).unwrap();
+
+    // Read the modified content
+    let result = fs::read_to_string(&test_file).unwrap();
+
+    // The key assertion: CARGO_BIN_EXE_foobar should become CARGO_BIN_EXE_baz_qux
+    // NOT CARGO_BIN_EXE_BAZ_QUX
+    assert!(
+        result.contains(r#"env!("CARGO_BIN_EXE_baz_qux")"#),
+        "Expected CARGO_BIN_EXE_baz_qux (lowercase), but got: {}",
+        result
+    );
+
+    // Other mixed patterns should also preserve the lowercase
+    assert!(
+        result.contains("PREFIX_baz_qux"),
+        "Expected PREFIX_baz_qux (lowercase suffix)"
+    );
+    assert!(
+        result.contains("DEBUG_baz_qux_enabled"),
+        "Expected DEBUG_baz_qux_enabled (lowercase in middle)"
+    );
+
+    // Regular lowercase replacements
+    assert!(result.contains("baz_qux_config"));
+    assert!(result.contains("simple_baz_qux"));
+}
+
+#[test]
+fn test_screaming_snake_with_lowercase_suffix() {
+    // More specific test for the SCREAMING_SNAKE_lowercase pattern
+    let temp_dir = TempDir::new().unwrap();
+    let test_file = temp_dir.path().join("build.rs");
+
+    let content = r#"
+// Build script with environment variables
+const CARGO_PKG_NAME_oldtool: &str = "oldtool";
+const CARGO_BIN_EXE_oldtool: &str = "/path/to/oldtool";
+const RUST_VERSION_oldtool: &str = "1.70.0";
+
+// Should not change fully uppercase
+const CARGO_OLDTOOL_VERSION: &str = "1.0.0";
+"#;
+
+    fs::write(&test_file, content).unwrap();
+
+    // Replace "oldtool" with "new_tool"
+    let mut plan = scan_repository(
+        temp_dir.path(),
+        "oldtool",
+        "new_tool",
+        &PlanOptions::default(),
+    )
+    .unwrap();
+
+    apply_plan(&mut plan, &ApplyOptions::default()).unwrap();
+
+    let result = fs::read_to_string(&test_file).unwrap();
+
+    // These should have lowercase replacements
+    assert!(
+        result.contains("CARGO_PKG_NAME_new_tool"),
+        "Expected lowercase new_tool after CARGO_PKG_NAME_"
+    );
+    assert!(
+        result.contains("CARGO_BIN_EXE_new_tool"),
+        "Expected lowercase new_tool after CARGO_BIN_EXE_"
+    );
+    assert!(
+        result.contains("RUST_VERSION_new_tool"),
+        "Expected lowercase new_tool after RUST_VERSION_"
+    );
+
+    // This should be fully uppercase since the original was fully uppercase
+    assert!(
+        result.contains("CARGO_NEW_TOOL_VERSION"),
+        "Expected uppercase NEW_TOOL when replacing within fully uppercase context"
+    );
+}