From d45b1219e9aa832c48a3c4503709dbde32434815 Mon Sep 17 00:00:00 2001
From: Dan Goodliffe <dan@randomdan.homeip.net>
Date: Mon, 9 Nov 2015 18:24:23 +0000
Subject: Add specific exception for invalid conversions during extract and
 tests over extract

---
 libdbpp/column.cpp              | 19 +++++++++++++++----
 libdbpp/column.h                | 13 +++++++++++++
 libdbpp/unittests/testUtils.cpp | 32 ++++++++++++++++++++++++++++++--
 libdbpp/unittests/util.sql      |  4 ++--
 4 files changed, 60 insertions(+), 8 deletions(-)

diff --git a/libdbpp/column.cpp b/libdbpp/column.cpp
index 81150a5..a29b80e 100644
--- a/libdbpp/column.cpp
+++ b/libdbpp/column.cpp
@@ -1,17 +1,27 @@
 #include "column.h"
 #include <boost/utility/enable_if.hpp>
 #include <exception>
+#include <buffer.h>
 
-DB::Column::Column(const Glib::ustring & n, unsigned int i) :
+namespace DB {
+Column::Column(const Glib::ustring & n, unsigned int i) :
 	colNo(i),
 	name(n)
 {
 }
 
-DB::Column::~Column()
+Column::~Column()
 {
 }
 
+InvalidConversion::InvalidConversion(const char * const f, const char * const t) : from(f), to(t) { }
+
+std::string
+InvalidConversion::message() const throw()
+{
+	return stringf("Invalid conversion from column type (%s) to value type (%s)", from, to);
+}
+
 template<typename T>
 class Extract : public DB::HandleField {
 	public:
@@ -28,7 +38,7 @@ class Extract : public DB::HandleField {
 		template <typename D, typename dummy = int>
 		void operator()(const D &,
 				typename boost::disable_if<std::is_convertible<D, T>, dummy>::type = 0) {
-			throw std::runtime_error("Invalid type conversion");
+			throw InvalidConversion(typeid(D).name(), typeid(T).name());
 		}
 
 		template <typename D, typename dummy = int>
@@ -42,7 +52,7 @@ class Extract : public DB::HandleField {
 
 #define COLUMNINTO(Type) \
 void \
-DB::Column::operator>>(Type & v) const \
+Column::operator>>(Type & v) const \
 { \
 	Extract<Type> e(v); \
 	apply(e); \
@@ -54,4 +64,5 @@ COLUMNINTO(double);
 COLUMNINTO(std::string);
 COLUMNINTO(boost::posix_time::ptime);
 COLUMNINTO(boost::posix_time::time_duration);
+}
 
diff --git a/libdbpp/column.h b/libdbpp/column.h
index 43d2687..d3475a3 100644
--- a/libdbpp/column.h
+++ b/libdbpp/column.h
@@ -6,8 +6,21 @@
 #include <boost/shared_ptr.hpp>
 #include <boost/optional.hpp>
 #include <visibility.h>
+#include <exception.h>
+#include "error.h"
 
 namespace DB {
+	/// Exception thrown on an attempt to convert betweem incompatible types.
+	class DLL_PUBLIC InvalidConversion : public AdHoc::Exception<Error> {
+		public:
+			InvalidConversion(const char * const, const char * const);
+
+		private:
+			std::string message() const throw() override;
+			const char * from;
+			const char * to;
+	};
+
 	/// Abstract class for something that can handle field data. See Column::apply.
 	class DLL_PUBLIC HandleField {
 		public:
diff --git a/libdbpp/unittests/testUtils.cpp b/libdbpp/unittests/testUtils.cpp
index b7947c7..e86d851 100644
--- a/libdbpp/unittests/testUtils.cpp
+++ b/libdbpp/unittests/testUtils.cpp
@@ -25,7 +25,7 @@ BOOST_AUTO_TEST_CASE( forEachRow )
 	sel->forEachRow<int64_t, double, std::string, boost::posix_time::ptime, boost::posix_time::time_duration, bool>(
 			[](auto a, auto b, auto c, auto d, auto e, auto f) {
 				BOOST_REQUIRE_EQUAL(1, a);
-				BOOST_REQUIRE_EQUAL(2.3, b);
+				BOOST_REQUIRE_CLOSE(4.3, b, 0.001);
 				BOOST_REQUIRE_EQUAL("Some text", c);
 				BOOST_REQUIRE_EQUAL(boost::posix_time::ptime_from_tm({ 17, 39, 13, 7, 10, 115, 0, 0, 0, 0, 0}), d);
 				BOOST_REQUIRE_EQUAL(boost::posix_time::time_duration(4, 3, 2), e);
@@ -41,7 +41,7 @@ BOOST_AUTO_TEST_CASE( forEachRowNulls )
 			[](auto a, auto b, auto c, auto d, auto e, auto f) {
 				BOOST_REQUIRE_EQUAL(2, a);
 				BOOST_REQUIRE(b);
-				BOOST_REQUIRE_EQUAL(2.3, *b);
+				BOOST_REQUIRE_CLOSE(4.3, *b, 0.001);
 				BOOST_REQUIRE_EQUAL("Some text", c);
 				BOOST_REQUIRE(!d);
 				BOOST_REQUIRE(!e);
@@ -74,3 +74,31 @@ BOOST_AUTO_TEST_CASE( columns )
 	BOOST_REQUIRE_THROW((*sel)[""], DB::ColumnDoesNotExist);
 }
 
+BOOST_AUTO_TEST_CASE( extract )
+{
+	auto db = DB::ConnectionPtr(DB::MockDatabase::openConnectionTo("pqmock"));
+	auto sel = DB::SelectCommandPtr(db->newSelectCommand("SELECT a, b, c FROM forEachRow WHERE f"));
+	BOOST_REQUIRE(sel->fetch());
+	int64_t lint;
+	double ldouble;
+	std::string lstring;
+	// Plain
+	(*sel)[0] >> lint;
+	(*sel)[1] >> ldouble;
+	(*sel)[2] >> lstring;
+	BOOST_REQUIRE_EQUAL(2, lint);
+	BOOST_REQUIRE_CLOSE(4.3, ldouble, 0.001);
+	BOOST_REQUIRE_EQUAL("Some text", lstring);
+	// Converted
+	(*sel)[1] >> lint;
+	(*sel)[0] >> ldouble;
+	BOOST_REQUIRE_EQUAL(4, lint);
+	BOOST_REQUIRE_CLOSE(2, ldouble, 0.001);
+	// Bad conversions
+	BOOST_REQUIRE_THROW((*sel)[2] >> lint, DB::InvalidConversion);
+	BOOST_REQUIRE_THROW((*sel)[2] >> ldouble, DB::InvalidConversion);
+	BOOST_REQUIRE_THROW((*sel)[1] >> lstring, DB::InvalidConversion);
+	BOOST_REQUIRE_THROW((*sel)[0] >> lstring, DB::InvalidConversion);
+	BOOST_REQUIRE(!sel->fetch());
+}
+
diff --git a/libdbpp/unittests/util.sql b/libdbpp/unittests/util.sql
index 04c6bf6..13391ea 100644
--- a/libdbpp/unittests/util.sql
+++ b/libdbpp/unittests/util.sql
@@ -5,6 +5,6 @@ CREATE TABLE foreachrow (
 		d timestamp without time zone,
 		e interval,
 		f boolean);
-INSERT INTO foreachrow(a, b, c, d, e, f) VALUES(1, 2.3, 'Some text', '2015-11-07 13:39:17', '04:03:02', true);
-INSERT INTO foreachrow(a, b, c, f) VALUES(2, 2.3, 'Some text', false);
+INSERT INTO foreachrow(a, b, c, d, e, f) VALUES(1, 4.3, 'Some text', '2015-11-07 13:39:17', '04:03:02', true);
+INSERT INTO foreachrow(a, b, c, f) VALUES(2, 4.3, 'Some text', false);
 
-- 
cgit v1.2.3