Provide a path conversion from snake_case to dashed-case

internal/common.bzl

@@ -178,6 +178,46 @@ def php_path(s):
     """
     return "/".join([capitalize(c) for c in s.split("/")])
 
+def snake_case(s):
+    """
+    Convert a path string from camelCase to snake_case.
+
+    Args:
+        s (string): The input string to be converted.
+
+    Returns:
+        (string): The converted string.
+
+    """
+    converted = ""
+    is_last_lower_case = False
+    for char in s.elems():
+        if char.isupper():
+            if is_last_lower_case:
+                converted+="_"+char
+                is_last_lower_case = False
+                continue
+        elif char.islower() or char.isdigit():
+            is_last_lower_case = True
+            converted+=char
+            continue
+        is_last_lower_case = False
+        converted+=char
+    return converted.lower()
+
+def dasherize(s):
+    """
+    Convert a path string from snake_case to dashed-case.
+
+    Args:
+        s (string): The input string to be converted.
+
+    Returns:
+        (string): The converted string.
+
+    """
+    return snake_case(s).replace("_", "-")
+
 def get_output_filename(src_file, pattern, proto_info):
     """
     Build the predicted filename for file generated by the given plugin.
@@ -249,6 +289,12 @@ def get_output_filename(src_file, pattern, proto_info):
         filename = pattern.replace("{basename|rust_keyword}", rust_keyword(basename))
     elif "{protopath|rust_keyword}" in pattern:
         filename = pattern.replace("{basename|rust_keyword}", rust_keyword(protopath))
+    elif "{protopath|dasherize}" in pattern:
+        filename = pattern.replace("{protopath|dasherize}", "/".join([
+            # Dasherize only the file name
+            protopath_partitions[0],
+            dasherize(protopath_partitions[2]),
+        ]))
     else:
         filename += basename + pattern