test: add string function test cases

bft/dialects/parser.py

@@ -14,8 +14,11 @@ def visit_scalar_function(self, func):
         local_name = self._get_or_else(func, "local_name", name)
         infix = self._get_or_else(func, "infix", False)
         postfix = self._get_or_else(func, "postfix", False)
+        skip = self._get_or_else(func, "skip", False)
         bad_kernels = self._visit_list(self.visit_kernel, func, "unsupported_kernels")
-        return DialectFunction(name, local_name, infix, postfix, required_opts, bad_kernels)
+        return DialectFunction(
+            name, local_name, infix, postfix, skip, required_opts, bad_kernels
+        )
 
     def visit(self, dfile):
         name = self._get_or_die(dfile, "name")

bft/dialects/types.py

@@ -1,5 +1,7 @@
 from typing import Dict, List, NamedTuple
 
+import pytest
+
 from bft.cases.types import Case, CaseLiteral, Literal, case_to_kernel_str
 from bft.core.function import Kernel
 
@@ -14,6 +16,7 @@ class DialectFunction(NamedTuple):
     local_name: str
     infix: bool
     postfix: bool
+    skip: bool
     required_options: Dict[str, str]
     unsupported_kernels: List[DialectKernel]
 
@@ -28,6 +31,7 @@ class SqlMapping(NamedTuple):
     local_name: str
     infix: bool
     postfix: bool
+    skip: bool
     should_pass: bool
     reason: str
 
@@ -100,18 +104,36 @@ def supports_kernel(self, function_name: str, kernel: Kernel) -> bool:
 
     def mapping_for_case(self, case: Case) -> SqlMapping:
         dfunc = self.__scalar_functions_by_name.get(case.function, None)
+        if dfunc.skip:
+            pytest.skip("Skipping unsupported function.")
         if dfunc is None:
             return None
 
         kernel_failure = self.__supports_case_kernel(dfunc, case.args, case.result)
         if kernel_failure is not None:
-            return SqlMapping(dfunc.local_name, dfunc.infix, dfunc.postfix, False, kernel_failure)
+            return SqlMapping(
+                dfunc.local_name,
+                dfunc.infix,
+                dfunc.postfix,
+                dfunc.skip,
+                False,
+                kernel_failure,
+            )
 
         option_failure = self.__supports_options(dfunc, case)
         if option_failure is not None:
-            return SqlMapping(dfunc.local_name, dfunc.infix, dfunc.postfix, False, option_failure)
-
-        return SqlMapping(dfunc.local_name, dfunc.infix, dfunc.postfix, True, None)
+            return SqlMapping(
+                dfunc.local_name,
+                dfunc.infix,
+                dfunc.postfix,
+                dfunc.skip,
+                False,
+                option_failure,
+            )
+
+        return SqlMapping(
+            dfunc.local_name, dfunc.infix, dfunc.postfix, dfunc.skip, True, None
+        )
 
 
 class DialectsLibrary(object):

bft/testers/postgres/runner.py

@@ -61,7 +61,14 @@ def run_sql_case(self, case: Case, mapping: SqlMapping) -> SqlCaseResult:
 
             arg_names = [f"arg{idx}" for idx in range(len(case.args))]
             joined_arg_names = ",".join(arg_names)
-            arg_vals = ",".join([literal_to_str(arg) for arg in case.args])
+            arg_vals = ",".join(
+                [
+                    "'" + literal_to_str(arg) + "'"
+                    if arg.type == "string" and arg.value is not None
+                    else literal_to_str(arg)
+                    for arg in case.args
+                ]
+            )
             self.conn.execute(
                 f"INSERT INTO my_table ({joined_arg_names}) VALUES ({arg_vals});"
             )

bft/testers/sqlite/runner.py

@@ -13,6 +13,7 @@
     "fp32": "REAL",
     "fp64": "REAL",
     "boolean": "BOOLEAN",
+    "string": "TEXT",
 }
 
 
@@ -51,7 +52,14 @@ def run_sql_case(self, case: Case, mapping: SqlMapping) -> SqlCaseResult:
 
             arg_names = [f"arg{idx}" for idx in range(len(case.args))]
             joined_arg_names = ",".join(arg_names)
-            arg_vals = ",".join([literal_to_str(arg) for arg in case.args])
+            arg_vals = ",".join(
+                [
+                    "'" + literal_to_str(arg) + "'"
+                    if arg.type == "string" and arg.value is not None
+                    else literal_to_str(arg)
+                    for arg in case.args
+                ]
+            )
             self.conn.execute(
                 f"INSERT INTO my_table ({joined_arg_names}) VALUES ({arg_vals});"
             )

bft/testers/velox/runner.py

@@ -5,7 +5,7 @@
 
 
 def is_type_supported(type):
-    return type in set({"i8", "i16", "i32", "i64", "fp32", "fp64", "boolean"})
+    return type in set({"i8", "i16", "i32", "i64", "fp32", "fp64", "boolean", "string"})
 
 
 class VeloxRunner(SqlCaseRunner):

cases/string/concat.yaml

@@ -0,0 +1,42 @@
+function: concat
+cases:
+  - group:
+      id: basic
+      description: Basic examples without any special cases
+    args:
+      - value: 'abcd'
+        type: string
+      - value: 'efg'
+        type: string
+    result:
+      value: 'abcdefg'
+      type: string
+  - group:
+      id: null_input
+      description: Examples with null as input
+    args:
+      - value: 'abcd'
+        type: string
+      - value: null
+        type: string
+    result:
+      value: null
+      type: string
+  - group: null_input
+    args:
+      - value: null
+        type: string
+      - value: 'abcd'
+        type: string
+    result:
+      value: null
+      type: string
+  - group: null_input
+    args:
+      - value: null
+        type: string
+      - value: null
+        type: string
+    result:
+      value: null
+      type: string

cases/string/like.yaml

@@ -0,0 +1,60 @@
+function: like
+cases:
+  - group:
+      id: basic
+      description: Basic examples without any special cases
+    args:
+      - value: 'abcdefg'
+        type: string
+      - value: 'abcdefg'
+        type: string
+    result:
+      value: true
+      type: boolean
+  - group: basic
+    args:
+      - value: 'abcdefg'
+        type: string
+      - value: 'abc'
+        type: string
+    result:
+      value: false
+      type: boolean
+  - group:
+      id: wildcard
+      description: Examples using wildcards
+    args:
+      - value: 'abcdefg'
+        type: string
+      - value: 'abc%'
+        type: string
+    result:
+      value: true
+      type: boolean
+  - group: wildcard
+    args:
+      - value: 'abcdefg'
+        type: string
+      - value: '%efg'
+        type: string
+    result:
+      value: true
+      type: boolean
+  - group: wildcard
+    args:
+      - value: 'abcdefg'
+        type: string
+      - value: '_bcdefg'
+        type: string
+    result:
+      value: true
+      type: boolean
+  - group: wildcard
+    args:
+      - value: 'abcdefg'
+        type: string
+      - value: 'abc_efg'
+        type: string
+    result:
+      value: true
+      type: boolean

cases/string/substring.yaml

@@ -0,0 +1,54 @@
+function: substring
+cases:
+  - group:
+      id: basic
+      description: Basic examples without any special cases
+    args:
+      - value: 'abcdefg'
+        type: string
+      - value: 1
+        type: i32
+      - value: 5
+        type: i32
+    result:
+      value: 'abcde'
+      type: string
+  - group:
+      id: zero_start
+      description: Example where start argument is zero
+    args:
+      - value: 'abcdefg'
+        type: string
+      - value: 0
+        type: i32
+      - value: 3
+        type: i32
+    result:
+      value: 'ab'
+      type: string
+  - group:
+      id: negative_start
+      description: Example where start argument is a negative integer
+    args:
+      - value: 'abcdefg'
+        type: string
+      - value: -3
+        type: i32
+      - value: 2
+        type: i32
+    result:
+      value: 'ef'
+      type: string
+  - group:
+      id: start_greater_than_length
+      description: Example where start argument greater than the length of the string
+    args:
+      - value: 'abcdefg'
+        type: string
+      - value: 10
+        type: i32
+      - value: 2
+        type: i32
+    result:
+      value: ''
+      type: string

dialects/postgres.yaml

@@ -144,3 +144,10 @@ scalar_functions:
           - i8
           - i8
         result: i8
+  - name: substring
+    skip: true
+  - name: concat
+    local_name: "||"
+    infix: True
+  - name: like
+    infix: True

dialects/sqlite.yaml

@@ -69,3 +69,9 @@ scalar_functions:
     local_name: "NULLIF"
     infix: False
   - name: coalesce
+  - name: substring
+  - name: concat
+    local_name: "||"
+    infix: True
+  - name: like
+    infix: True

dialects/velox_presto.yaml

@@ -81,3 +81,7 @@ scalar_functions:
     local_name: "!="
     infix: True
   - name: coalesce
+  - name: substring
+    local_name: substr
+  - name: concat
+  - name: like