1 files changed, 102 insertions, 0 deletions
diff --git a/tests/test_regular_languages.py b/tests/test_regular_languages.py
new file mode 100644
index 0000000..deef6b8
--- /dev/null
+++ b/tests/test_regular_languages.py
@@ -0,0 +1,102 @@
+from __future__ import annotations
+
+from prompt_toolkit.completion import CompleteEvent, Completer, Completion
+from prompt_toolkit.contrib.regular_languages import compile
+from prompt_toolkit.contrib.regular_languages.compiler import Match, Variables
+from prompt_toolkit.contrib.regular_languages.completion import GrammarCompleter
+from prompt_toolkit.document import Document
+
+
+def test_simple_match():
+    g = compile("hello|world")
+
+    m = g.match("hello")
+    assert isinstance(m, Match)
+
+    m = g.match("world")
+    assert isinstance(m, Match)
+
+    m = g.match("somethingelse")
+    assert m is None
+
+
+def test_variable_varname():
+    """
+    Test `Variable` with varname.
+    """
+    g = compile("((?P<varname>hello|world)|test)")
+
+    m = g.match("hello")
+    variables = m.variables()
+    assert isinstance(variables, Variables)
+    assert variables.get("varname") == "hello"
+    assert variables["varname"] == "hello"
+
+    m = g.match("world")
+    variables = m.variables()
+    assert isinstance(variables, Variables)
+    assert variables.get("varname") == "world"
+    assert variables["varname"] == "world"
+
+    m = g.match("test")
+    variables = m.variables()
+    assert isinstance(variables, Variables)
+    assert variables.get("varname") is None
+    assert variables["varname"] is None
+
+
+def test_prefix():
+    """
+    Test `match_prefix`.
+    """
+    g = compile(r"(hello\ world|something\ else)")
+
+    m = g.match_prefix("hello world")
+    assert isinstance(m, Match)
+
+    m = g.match_prefix("he")
+    assert isinstance(m, Match)
+
+    m = g.match_prefix("")
+    assert isinstance(m, Match)
+
+    m = g.match_prefix("som")
+    assert isinstance(m, Match)
+
+    m = g.match_prefix("hello wor")
+    assert isinstance(m, Match)
+
+    m = g.match_prefix("no-match")
+    assert m.trailing_input().start == 0
+    assert m.trailing_input().stop == len("no-match")
+
+    m = g.match_prefix("hellotest")
+    assert m.trailing_input().start == len("hello")
+    assert m.trailing_input().stop == len("hellotest")
+
+
+def test_completer():
+    class completer1(Completer):
+        def get_completions(self, document, complete_event):
+            yield Completion("before-%s-after" % document.text, -len(document.text))
+            yield Completion("before-%s-after-B" % document.text, -len(document.text))
+
+    class completer2(Completer):
+        def get_completions(self, document, complete_event):
+            yield Completion("before2-%s-after2" % document.text, -len(document.text))
+            yield Completion("before2-%s-after2-B" % document.text, -len(document.text))
+
+    # Create grammar.  "var1" + "whitespace" + "var2"
+    g = compile(r"(?P<var1>[a-z]*) \s+ (?P<var2>[a-z]*)")
+
+    # Test 'get_completions()'
+    completer = GrammarCompleter(g, {"var1": completer1(), "var2": completer2()})
+    completions = list(
+        completer.get_completions(Document("abc def", len("abc def")), CompleteEvent())
+    )
+
+    assert len(completions) == 2
+    assert completions[0].text == "before2-def-after2"
+    assert completions[0].start_position == -3
+    assert completions[1].text == "before2-def-after2-B"
+    assert completions[1].start_position == -3