message: Support prepending payloads

Needed solely so that we can support adding the necessary
bits for oem and group commands. We shouldn't be using this anywhere
else, which is why it is not generalized to non-payload types.

Change-Id: I6573f981fbe68cebb89abcdfb3de5de5d139e1e0
Signed-off-by: William A. Kennington III <wak@google.com>

1 files changed, 26 insertions, 0 deletions

diff --git a/test/message/pack.cpp b/test/message/pack.cpp
index 7fb67ba..9e88f2b 100644
--- a/test/message/pack.cpp
+++ b/test/message/pack.cpp
@@ -306,6 +306,32 @@ TEST(PackBasics, PayloadOtherUnaligned)
     EXPECT_EQ(p.raw, std::vector<uint8_t>({0b1}));
 }
 
+TEST(PackBasics, PrependPayload)
+{
+    ipmi::message::Payload p;
+    EXPECT_EQ(p.pack(true), 0);
+    EXPECT_EQ(p.prepend(ipmi::message::Payload({0x24, 0x30})), 0);
+    EXPECT_EQ(p.raw, std::vector<uint8_t>({0x24, 0x30, 0b1}));
+}
+
+TEST(PackBasics, PrependPayloadUnaligned)
+{
+    ipmi::message::Payload p;
+    p.appendBits(1, 1);
+    EXPECT_EQ(p.prepend(ipmi::message::Payload({0x24})), 1);
+    p.drain();
+    EXPECT_EQ(p.raw, std::vector<uint8_t>({0b1}));
+}
+
+TEST(PackBasics, PrependPayloadOtherUnaligned)
+{
+    ipmi::message::Payload p, q;
+    q.appendBits(1, 1);
+    EXPECT_EQ(p.pack(true), 0);
+    EXPECT_EQ(p.prepend(q), 1);
+    EXPECT_EQ(p.raw, std::vector<uint8_t>({0b1}));
+}
+
 TEST(PackAdvanced, Uints)
 {
     // all elements will be processed in order, with each multi-byte