Deduplicate commas in generated magic prompts (#749)

Fixes #645

sd_dynamic_prompts/magic_prompt.py

@@ -1,3 +1,4 @@
+import re
 from itertools import zip_longest
 
 from dynamicprompts.generators.magicprompt import MagicPromptGenerator
@@ -8,6 +9,14 @@
 )
 
 
+def massage_prompt(prompt: str) -> str:
+    # Coalesce repeated punctuation to a single instance
+    prompt = re.sub(r"([.,])\1+", r"\1", prompt)
+    # Remove leading/trailing whitespace
+    prompt = prompt.strip()
+    return prompt
+
+
 class SpecialSyntaxAwareMagicPromptGenerator(MagicPromptGenerator):
     """
     Magic Prompt generator that is aware of A1111 special syntax (LoRA, hypernet, etc.).
@@ -18,7 +27,10 @@ def _generate_magic_prompts(self, orig_prompts: list[str]) -> list[str]:
             *(remove_a1111_special_syntax_chunks(p) for p in orig_prompts),
         )
         # `transformers` is rather particular that the input is a list, not a tuple
-        magic_prompts = super()._generate_magic_prompts(list(orig_prompts))
+        magic_prompts = [
+            massage_prompt(prompt)
+            for prompt in super()._generate_magic_prompts(list(orig_prompts))
+        ]
         # in case we somehow get less magic prompts than we started with,
         # use zip_longest instead of zip.
         return [

tests/prompts/test_magic_prompts.py

@@ -2,7 +2,7 @@ def fake_generator(prompts, **_kwargs):
     assert isinstance(prompts, list)  # be as particular as transformers is
     for prompt in prompts:
         assert "<" not in prompt  # should have been stripped
-        yield [{"generated_text": f"magical {prompt}"}]
+        yield [{"generated_text": f"magical {prompt},,,, wow, so nice"}]
 
 
 def test_magic_prompts(monkeypatch):
@@ -30,3 +30,6 @@ def test_magic_prompts(monkeypatch):
         assert "<hypernet:v18000Steps:1>" in prompt
         # but we should expect to see some magic
         assert prompt.startswith("magical ")
+        # See that multiple commas are coalesced
+        assert ",,,," not in prompt
+        assert ", wow, so nice" in prompt