Merge pull request #42 from Azure/#40-literal-dynamic

fix #40 literal dynamic

pykusto/functions.py

@@ -1,3 +1,4 @@
+import json
 from typing import Union
 
 from pykusto.expressions import Column, NumberType, NumberExpression, TimespanType, \
@@ -583,16 +584,20 @@ def startofyear(expr: DatetimeType, offset: NumberType = None) -> DatetimeExpres
     return expr.startofyear(offset)
 
 
-def strcat(expr1: StringType, expr2: StringType, *exprs: StringType) -> StringExpression:
-    res = 'strcat({}, {}'.format(to_kql(expr1),
-                                 to_kql(expr2))
-    if len(exprs) > 0:
-        res = res + ', ' + ', '.join([to_kql(expr) for expr in exprs])
-    return StringExpression(KQL(res + ')'))
+def strcat(*strings: StringType) -> StringExpression:
+    if len(strings) < 2:
+        raise ValueError("strcat requires at least two arguments")
+    return StringExpression(KQL('strcat({})'.format(', '.join(to_kql(s) for s in strings))))
+
+
+def to_literal_dynamic(d: DynamicType) -> KQL:
+    if isinstance(d, BaseExpression):
+        return d.kql
+    return KQL('dynamic({})'.format(json.dumps(d)))
 
 
 def strcat_array(expr: ArrayType, delimiter: StringType) -> StringExpression:
-    return StringExpression(KQL('strcat_array({}, {})'.format(to_kql(expr), to_kql(delimiter))))
+    return StringExpression(KQL('strcat_array({}, {})'.format(to_literal_dynamic(expr), to_kql(delimiter))))
 
 
 def strcat_delim(delimiter: StringType, expr1: StringType, expr2: StringType, *exprs: StringType) -> StringExpression:

pykusto/kql_converters.py

@@ -29,7 +29,7 @@ def timedelta_to_kql(td: timedelta) -> KQL:
 @kql_converter(Mapping, List, Tuple)
 def dynamic_to_kql(d: Union[Mapping, List, Tuple]) -> KQL:
     query = list(json.dumps(d))
-    # Issue #11
+    # Convert square brackets to round brackets (Issue #11)
     counter = 0
     prev = ""
     for i, c in enumerate(query):

test/test_functions.py

@@ -1,5 +1,4 @@
 import datetime
-import unittest
 
 from pykusto import functions as f
 from pykusto.expressions import column_generator as col
@@ -372,7 +371,6 @@ class TestFunction(TestBase):
             Query().extend(f.strcat_delim('-', ',', col.foo)).render()
         )
 
-    @unittest.skip("Enabled after #40 is fixed")
     def test_strcat_array(self):
         self.assertEqual(
             " | where (strcat_array(foo, \",\")) == \"A,B,C\"",