Fix ap_is -> apis (#2536)

.generator/src/generator/formatter.py

@@ -4,7 +4,7 @@
 
 import dateutil.parser
 
-from .utils import snake_case, camel_case, untitle_case, schema_name
+from .utils import safe_snake_case, snake_case, camel_case, untitle_case, schema_name
 
 PRIMITIVE_TYPES = ["string", "number", "boolean", "integer"]
 
@@ -81,7 +81,7 @@ def block_comment(comment, prefix="#", first_line=True):
 
 
 def model_filename(name):
-    filename = snake_case(name)
+    filename = safe_snake_case(name)
     last = filename.split("_")[-1]
     if last in SUFFIXES:
         filename += "_"

.generator/src/generator/utils.py

@@ -6,6 +6,8 @@
 PATTERN_LEADING_ALPHA = re.compile(r"(.)([A-Z][a-z]+)")
 PATTERN_FOLLOWING_ALPHA = re.compile(r"([a-z0-9])([A-Z])")
 PATTERN_WHITESPACE = re.compile(r"\W")
+# Other client generators have more edge cases defined but adding them here could cause backwards-incompatible breaking changes.
+EDGE_CASES = {"APIs": "Apis"}
 
 
 def snake_case(value):
@@ -16,6 +18,12 @@ def snake_case(value):
     return PATTERN_DOUBLE_UNDERSCORE.sub("_", s1)
 
 
+def safe_snake_case(value):
+    for token, replacement in EDGE_CASES.items():
+        value = value.replace(token, replacement)
+    return snake_case(value)
+
+
 def upperfirst(value):
     return value[0].upper() + value[1:]