fixing text to float convertion (ronen-fr #42) (#64)

Signed-off-by: gal salomon <gal.salomon@gmail.com>

Author: galsalomon66

include/s3select_functions.h

@@ -599,42 +599,43 @@ struct _fn_to_int : public base_function
 
 struct _fn_to_float : public base_function
 {
-
   value var_result;
-  value v_from;
 
   bool operator()(bs_stmt_vec_t* args, variable* result) override
   {
-    char* perr;
-    double d=0;
     value v = (*args->begin())->eval();
 
-    if (v.type == value::value_En_t::STRING)
+    switch (v.type) {
+
+    case value::value_En_t::STRING:
     {
-      errno = 0;
-      d = strtod(v.str(), &perr) ;  //TODO check error before constructor
-      if ((errno == ERANGE && (d == LONG_MAX || d == LONG_MIN)) || (errno != 0 && d == 0)) {
+      char* pend;
+      double d = strtod(v.str(), &pend);
+      if (errno == ERANGE) {
         throw base_s3select_exception("converted value would fall out of the range of the result type!");
-        return false;  
-    }
-    
-    if (*perr != '\0') {
-      throw base_s3select_exception("characters after float!");
-      return false;
-    }
-  }
-    else if (v.type == value::value_En_t::FLOAT)
-    {
-      d = v.dbl();
+      }
+      if (pend == v.str()) {
+        // no number found
+        throw base_s3select_exception("text cannot be converted to a number");
+      }
+      if (*pend) {
+        throw base_s3select_exception("extra characters after the number");
+      }
+
+      var_result = d;
     }
-    else
-    {
-      d = v.i64();
+    break;
+
+    case value::value_En_t::FLOAT:
+      var_result = v.dbl();
+      break;
+
+    default:
+      var_result = v.i64();
+      break;
     }
 
-    var_result = d;
     *result = var_result;
-
     return true;
   }
 

test/s3select_test.cpp

@@ -689,7 +689,7 @@ int count_string(std::string in,std::string substr)
 }
 
 
-void test_single_column_single_row(const char* input_query,const char* expected_result)
+void test_single_column_single_row(const char* input_query,const char* expected_result,const char * error_description = 0)
 {
     s3select s3select_syntax;
     auto status = s3select_syntax.parse_query(input_query);
@@ -704,6 +704,17 @@ void test_single_column_single_row(const char* input_query,const char* expected_
         false, // dont skip last line
         true   // aggregate call
         );
+
+    if(strcmp(expected_result,"#failure#") == 0)
+    {
+      if (status==0 && s3select_result.compare("#failure#")==0)
+      {
+	  ASSERT_TRUE(0);
+      }
+      ASSERT_EQ(s3_csv_object.get_error_description(),error_description);
+      return;
+    }
+
     ASSERT_EQ(status, 0);
     ASSERT_EQ(s3select_result, std::string(expected_result));
 }
@@ -3426,6 +3437,13 @@ TEST(TestS3selectFunctions, boolcast)
   test_single_column_single_row("select cast('a' as bool) from s3object;","false,\n");
 }
 
+TEST(TestS3selectFunctions, floatcast)
+{
+  test_single_column_single_row("select cast('1234a' as float) from s3object;","#failure#","extra characters after the number");
+  test_single_column_single_row("select cast('a1234' as float) from s3object;","#failure#","text cannot be converted to a number");
+  test_single_column_single_row("select cast('999e+999' as float) from s3object;","#failure#","converted value would fall out of the range of the result type!");
+}
+
 TEST(TestS3selectFunctions, predicate_as_projection_column)
 {
   std::string input;