From 4557c0f31de339761bb08cea50905f58f058a8a3 Mon Sep 17 00:00:00 2001
From: Richard Tia <richie.tia@gmail.com>
Date: Thu, 4 May 2023 10:51:06 -0700
Subject: [PATCH] test: add concat function

---
 bft/testers/postgres/runner.py |  2 +-
 bft/testers/sqlite/runner.py   |  2 +-
 cases/string/concat.yaml       | 42 ++++++++++++++++++++++++++++++++++
 dialects/postgres.yaml         |  5 +++-
 dialects/sqlite.yaml           |  5 +++-
 dialects/velox_presto.yaml     |  5 +++-
 6 files changed, 56 insertions(+), 5 deletions(-)
 create mode 100644 cases/string/concat.yaml

diff --git a/bft/testers/postgres/runner.py b/bft/testers/postgres/runner.py
index 1b3b392c..af8bf9ed 100644
--- a/bft/testers/postgres/runner.py
+++ b/bft/testers/postgres/runner.py
@@ -59,7 +59,7 @@ def run_sql_case(self, case: Case, mapping: SqlMapping) -> SqlCaseResult:
             arg_vals = ",".join(
                 [
                     "'" + literal_to_str(arg) + "'"
-                    if arg.type == "string"
+                    if arg.type == "string" and arg.value is not None
                     else literal_to_str(arg)
                     for arg in case.args
                 ]
diff --git a/bft/testers/sqlite/runner.py b/bft/testers/sqlite/runner.py
index 7662ecd7..98bfff60 100644
--- a/bft/testers/sqlite/runner.py
+++ b/bft/testers/sqlite/runner.py
@@ -50,7 +50,7 @@ def run_sql_case(self, case: Case, mapping: SqlMapping) -> SqlCaseResult:
             arg_vals = ",".join(
                 [
                     "'" + literal_to_str(arg) + "'"
-                    if arg.type == "string"
+                    if arg.type == "string" and arg.value is not None
                     else literal_to_str(arg)
                     for arg in case.args
                 ]
diff --git a/cases/string/concat.yaml b/cases/string/concat.yaml
new file mode 100644
index 00000000..3791b2bf
--- /dev/null
+++ b/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
\ No newline at end of file
diff --git a/dialects/postgres.yaml b/dialects/postgres.yaml
index 88336560..147ca61c 100644
--- a/dialects/postgres.yaml
+++ b/dialects/postgres.yaml
@@ -56,4 +56,7 @@ scalar_functions:
     infix: False
   - name: substring
     local_name: substring
-    infix: False
\ No newline at end of file
+    infix: False
+  - name: concat
+    local_name: "||"
+    infix: True
diff --git a/dialects/sqlite.yaml b/dialects/sqlite.yaml
index 196bf00c..6c1bd77a 100644
--- a/dialects/sqlite.yaml
+++ b/dialects/sqlite.yaml
@@ -40,4 +40,7 @@ scalar_functions:
     infix: False
   - name: substring
     local_name: substring
-    infix: False
\ No newline at end of file
+    infix: False
+  - name: concat
+    local_name: "||"
+    infix: True
diff --git a/dialects/velox_presto.yaml b/dialects/velox_presto.yaml
index 6c5877e2..ebe5cb19 100644
--- a/dialects/velox_presto.yaml
+++ b/dialects/velox_presto.yaml
@@ -64,4 +64,7 @@ scalar_functions:
     infix: False
   - name: substring
     local_name: substring
-    infix: False
\ No newline at end of file
+    infix: False
+  - name: concat
+    local_name: concat
+    infix: False