refactor: move more tests, delete some providers tests (#1382)

Move unittests to tests/unittests. Gradually nuking tests from
providers/tests/ and unifying them into tests/api (which are e2e tests
using SDK types)

## Test Plan

`pytest -s -v tests/unittests/`

tests/unittests/models/test_system_prompts.py

@@ -0,0 +1,198 @@
+# Copyright (c) Meta Platforms, Inc. and affiliates.
+# All rights reserved.
+#
+# This source code is licensed under the terms described in the LICENSE file in
+# the root directory of this source tree.
+
+# Copyright (c) Meta Platforms, Inc. and affiliates.
+# All rights reserved.
+#
+# This source code is licensed under the terms described in the LICENSE file in
+# top-level folder for each specific model found within the models/ directory at
+# the top-level of this source tree.
+
+import textwrap
+import unittest
+from datetime import datetime
+
+from llama_stack.models.llama.llama3.prompt_templates import (
+    BuiltinToolGenerator,
+    FunctionTagCustomToolGenerator,
+    JsonCustomToolGenerator,
+    PythonListCustomToolGenerator,
+    SystemDefaultGenerator,
+)
+
+
+class PromptTemplateTests(unittest.TestCase):
+    def check_generator_output(self, generator, expected_text):
+        example = generator.data_examples()[0]
+
+        pt = generator.gen(example)
+        text = pt.render()
+        # print(text)  # debugging
+        assert text == expected_text, f"Expected:\n{expected_text}\nActual:\n{text}"
+
+    def test_system_default(self):
+        generator = SystemDefaultGenerator()
+        today = datetime.now().strftime("%d %B %Y")
+        expected_text = f"Cutting Knowledge Date: December 2023\nToday Date: {today}"
+        self.check_generator_output(generator, expected_text)
+
+    def test_system_builtin_only(self):
+        generator = BuiltinToolGenerator()
+        expected_text = textwrap.dedent(
+            """
+            Environment: ipython
+            Tools: brave_search, wolfram_alpha
+            """
+        )
+        self.check_generator_output(generator, expected_text.strip("\n"))
+
+    def test_system_custom_only(self):
+        self.maxDiff = None
+        generator = JsonCustomToolGenerator()
+        expected_text = textwrap.dedent(
+            """
+            Answer the user's question by making use of the following functions if needed.
+            If none of the function can be used, please say so.
+            Here is a list of functions in JSON format:
+            {
+                "type": "function",
+                "function": {
+                    "name": "trending_songs",
+                    "description": "Returns the trending songs on a Music site",
+                    "parameters": {
+                        "type": "object",
+                        "properties": [
+                            {
+                                "n": {
+                                    "type": "object",
+                                    "description": "The number of songs to return"
+                                }
+                            },
+                            {
+                                "genre": {
+                                    "type": "object",
+                                    "description": "The genre of the songs to return"
+                                }
+                            }
+                        ],
+                        "required": ["n"]
+                    }
+                }
+            }
+
+            Return function calls in JSON format.
+            """
+        )
+        self.check_generator_output(generator, expected_text.strip("\n"))
+
+    def test_system_custom_function_tag(self):
+        self.maxDiff = None
+        generator = FunctionTagCustomToolGenerator()
+        expected_text = textwrap.dedent(
+            """
+            You have access to the following functions:
+
+            Use the function 'trending_songs' to 'Returns the trending songs on a Music site':
+            {"name": "trending_songs", "description": "Returns the trending songs on a Music site", "parameters": {"genre": {"description": "The genre of the songs to return", "param_type": "str", "required": false}, "n": {"description": "The number of songs to return", "param_type": "int", "required": true}}}
+
+            Think very carefully before calling functions.
+            If you choose to call a function ONLY reply in the following format with no prefix or suffix:
+
+            <function=example_function_name>{"example_name": "example_value"}</function>
+
+            Reminder:
+            - If looking for real time information use relevant functions before falling back to brave_search
+            - Function calls MUST follow the specified format, start with <function= and end with </function>
+            - Required parameters MUST be specified
+            - Only call one function at a time
+            - Put the entire function call reply on one line
+            """
+        )
+        self.check_generator_output(generator, expected_text.strip("\n"))
+
+    def test_llama_3_2_system_zero_shot(self):
+        generator = PythonListCustomToolGenerator()
+        expected_text = textwrap.dedent(
+            """
+            You are a helpful assistant. You have access to functions, but you should only use them if they are required.
+            You are an expert in composing functions. You are given a question and a set of possible functions.
+            Based on the question, you may or may not need to make one function/tool call to achieve the purpose.
+
+            If you decide to invoke any of the function(s), you MUST put it in the format of [func_name1(params_name1=params_value1, params_name2=params_value2...), func_name2(params)]
+            You SHOULD NOT include any other text in the response.
+
+            Here is a list of functions in JSON format that you can invoke.
+
+            [
+                {
+                    "name": "get_weather",
+                    "description": "Get weather info for places",
+                    "parameters": {
+                        "type": "dict",
+                        "required": ["city"],
+                        "properties": {
+                            "city": {
+                                "type": "string",
+                                "description": "The name of the city to get the weather for"
+                            },
+                            "metric": {
+                                "type": "string",
+                                "description": "The metric for weather. Options are: celsius, fahrenheit",
+                                "default": "celsius"
+                            }
+                        }
+                    }
+                }
+            ]
+            """
+        )
+        self.check_generator_output(generator, expected_text.strip("\n"))
+
+    def test_llama_3_2_provided_system_prompt(self):
+        generator = PythonListCustomToolGenerator()
+        expected_text = textwrap.dedent(
+            """
+            Overriding message.
+
+            If you decide to invoke any of the function(s), you MUST put it in the format of [func_name1(params_name1=params_value1, params_name2=params_value2...), func_name2(params)]
+            You SHOULD NOT include any other text in the response.
+
+            Here is a list of functions in JSON format that you can invoke.
+
+            [
+                {
+                    "name": "get_weather",
+                    "description": "Get weather info for places",
+                    "parameters": {
+                        "type": "dict",
+                        "required": ["city"],
+                        "properties": {
+                            "city": {
+                                "type": "string",
+                                "description": "The name of the city to get the weather for"
+                            },
+                            "metric": {
+                                "type": "string",
+                                "description": "The metric for weather. Options are: celsius, fahrenheit",
+                                "default": "celsius"
+                            }
+                        }
+                    }
+                }
+            ]"""
+        )
+        user_system_prompt = textwrap.dedent(
+            """
+            Overriding message.
+
+            {{ function_description }}
+            """
+        )
+        example = generator.data_examples()[0]
+
+        pt = generator.gen(example, user_system_prompt)
+        text = pt.render()
+        assert text == expected_text, f"Expected:\n{expected_text}\nActual:\n{text}"