tests(pyargus): add tests for parsing expressions

pyargus/tests/utils/expr_gen.py

@@ -0,0 +1,73 @@
+"""Hypothesis strategies to generate Argus expressions
+"""
+import hypothesis.strategies as st
+from hypothesis.extra.lark import from_lark
+from lark import Lark, Transformer
+
+
+class T(Transformer):
+    def INT(self, tok):  # noqa: N802,ANN # type: ignore
+        "Convert the value of `tok` from string to int, while maintaining line number & column."
+        return tok.update(value=int(tok) // 2**64)
+
+
+ARGUS_EXPR_GRAMMAR = Lark(
+    r"""
+
+TRUE: "true" | "TRUE"
+FALSE: "false" | "FALSE"
+BOOLEAN: TRUE | FALSE
+
+IDENT: ESCAPED_STRING | CNAME
+
+num_expr: num_expr "*" num_expr
+        | num_expr "/" num_expr
+        | num_expr "+" num_expr
+        | num_expr "-" num_expr
+        | "-" num_expr
+        | NUMBER
+        | IDENT
+        | "(" num_expr ")"
+
+cmp_expr: num_expr ">=" num_expr
+        | num_expr "<=" num_expr
+        | num_expr "<" num_expr
+        | num_expr ">" num_expr
+        | num_expr "==" num_expr
+        | num_expr "!=" num_expr
+
+INTERVAL: "[" INT? "," INT? "]"
+
+bool_expr: bool_expr "&&" bool_expr
+         | bool_expr "||" bool_expr
+         | bool_expr "<=>" bool_expr
+         | bool_expr "->" bool_expr
+         | bool_expr "^" bool_expr
+         | bool_expr WS_INLINE "U" WS_INLINE INTERVAL? bool_expr
+         | "!" bool_expr
+         | "G" WS_INLINE INTERVAL? bool_expr
+         | "F" WS_INLINE INTERVAL? bool_expr
+         | cmp_expr
+         | BOOLEAN
+         | IDENT
+         | "(" bool_expr ")"
+
+phi: bool_expr
+
+%import common.ESCAPED_STRING
+%import common.CNAME
+%import common.NUMBER
+%import common.INT
+%import common.WS
+%import common.WS_INLINE
+%ignore WS
+
+""",
+    start="phi",
+)
+
+
+@st.composite
+def argus_expr(draw: st.DrawFn) -> str:
+    """Strategy to generate an Argus STL expression from a pre-defined grammar"""
+    return draw(from_lark(ARGUS_EXPR_GRAMMAR, start="phi"))