Add tests for suggester.

tests/suggester/test_suggest_from_list.py

@@ -0,0 +1,55 @@
+from __future__ import annotations
+
+import pytest
+
+from textual.dom import DOMNode
+from textual.suggester import SuggestFromList, SuggestionReady
+
+countries = ["England", "Portugal", "Scotland", "portugal", "PORTUGAL"]
+
+
+class LogListNode(DOMNode):
+    def __init__(self, log_list: list[tuple[str, str]]) -> None:
+        self.log_list = log_list
+
+    def post_message(self, message: SuggestionReady):
+        # We hijack post_message so we can intercept messages without creating a full app.
+        self.log_list.append((message.suggestion, message.value))
+
+
+async def test_first_suggestion_has_priority():
+    suggester = SuggestFromList(countries)
+
+    assert "Portugal" == await suggester.get_suggestion("P")
+
+
+@pytest.mark.parametrize("value", ["s", "S", "sc", "sC", "Sc", "SC"])
+async def test_case_insensitive_suggestions(value):
+    suggester = SuggestFromList(countries, case_sensitive=False)
+    log = []
+
+    await suggester._get_suggestion(LogListNode(log), value)
+    assert log == [("Scotland", value)]
+
+
+@pytest.mark.parametrize(
+    "value",
+    [
+        "p",
+        "P",
+        "po",
+        "Po",
+        "pO",
+        "PO",
+        "port",
+        "Port",
+        "pORT",
+        "PORT",
+    ],
+)
+async def test_first_suggestion_has_priority_case_insensitive(value):
+    suggester = SuggestFromList(countries, case_sensitive=False)
+    log = []
+
+    await suggester._get_suggestion(LogListNode(log), value)
+    assert log == [("Portugal", value)]

tests/suggester/test_suggester.py

@@ -0,0 +1,111 @@
+from __future__ import annotations
+
+import pytest
+
+from textual.dom import DOMNode
+from textual.suggester import Suggester, SuggestionReady
+
+
+class FillSuggester(Suggester):
+    async def get_suggestion(self, value: str):
+        if len(value) <= 10:
+            return f"{value:x<10}"
+
+
+class LogListNode(DOMNode):
+    def __init__(self, log_list: list[tuple[str, str]]) -> None:
+        self.log_list = log_list
+
+    def post_message(self, message: SuggestionReady):
+        # We hijack post_message so we can intercept messages without creating a full app.
+        self.log_list.append((message.suggestion, message.value))
+
+
+async def test_cache_on():
+    log = []
+
+    class MySuggester(Suggester):
+        async def get_suggestion(self, value: str):
+            log.append(value)
+            return value
+
+    suggester = MySuggester(use_cache=True)
+    await suggester._get_suggestion(DOMNode(), "hello")
+    assert log == ["hello"]
+    await suggester._get_suggestion(DOMNode(), "hello")
+    assert log == ["hello"]
+
+
+async def test_cache_off():
+    log = []
+
+    class MySuggester(Suggester):
+        async def get_suggestion(self, value: str):
+            log.append(value)
+            return value
+
+    suggester = MySuggester(use_cache=False)
+    await suggester._get_suggestion(DOMNode(), "hello")
+    assert log == ["hello"]
+    await suggester._get_suggestion(DOMNode(), "hello")
+    assert log == ["hello", "hello"]
+
+
+async def test_suggestion_ready_message():
+    log = []
+    suggester = FillSuggester()
+    await suggester._get_suggestion(LogListNode(log), "hello")
+    assert log == [("helloxxxxx", "hello")]
+    await suggester._get_suggestion(LogListNode(log), "world")
+    assert log == [("helloxxxxx", "hello"), ("worldxxxxx", "world")]
+
+
+async def test_no_message_if_no_suggestion():
+    log = []
+    suggester = FillSuggester()
+    await suggester._get_suggestion(LogListNode(log), "this is a longer string")
+    assert log == []
+
+
+async def test_suggestion_ready_message_on_cache_hit():
+    log = []
+    suggester = FillSuggester(use_cache=True)
+    await suggester._get_suggestion(LogListNode(log), "hello")
+    assert log == [("helloxxxxx", "hello")]
+    await suggester._get_suggestion(LogListNode(log), "hello")
+    assert log == [("helloxxxxx", "hello"), ("helloxxxxx", "hello")]
+
+
+@pytest.mark.parametrize(
+    "value",
+    [
+        "hello",
+        "HELLO",
+        "HeLlO",
+        "Hello",
+        "hELLO",
+    ],
+)
+async def test_case_insensitive_suggestions(value):
+    class MySuggester(Suggester):
+        async def get_suggestion(self, value: str):
+            assert "hello" == value
+
+    suggester = MySuggester(use_cache=False, case_sensitive=False)
+    await suggester._get_suggestion(DOMNode(), value)
+
+
+async def test_case_insensitive_cache_hits():
+    count = 0
+
+    class MySuggester(Suggester):
+        async def get_suggestion(self, value: str):
+            nonlocal count
+            count += 1
+            return value + "abc"
+
+    suggester = MySuggester(use_cache=True, case_sensitive=False)
+    hellos = ["hello", "HELLO", "HeLlO", "Hello", "hELLO"]
+    for hello in hellos:
+        await suggester._get_suggestion(DOMNode(), hello)
+    assert count == 1