lib/http: refactoring "multipart/form-data" parameters in ClientRequest

Previously, ClientRequest with type RequestTypeMultipartForm pass the
type "map[string][]byte" in Params.
This type hold the file upload, where key is the file name and []byte is
content of file.
Unfortunately, this model does not correct because a
"multipart/form-data" can contains different field name and file name,
for example

  --boundary
  Content-Disposition: form-data; name="field0"; filename="file0"
  Content-Type: application/octet-stream

  <Content of file0>

This changes fix this by changing the parameter type for
RequestTypeMultipartForm to [*multipart.Form], which affect several
functions including [Client.PutFormData] and [GenerateFormData].

We also add new function [CreateMultipartFileHeader] to help creating
[multipart.FileHeader] from raw bytes, that can be assigned to
[*multipart.Form].

1 files changed, 22 insertions, 0 deletions

diff --git a/lib/http/testdata/GenerateFormData_test.txt b/lib/http/testdata/GenerateFormData_test.txt
new file mode 100644
index 00000000..b209e07f
--- /dev/null
+++ b/lib/http/testdata/GenerateFormData_test.txt
@@ -0,0 +1,22 @@
+
+>>> file0
+Content of file0.
+
+<<< file0.ContentType
+multipart/form-data; boundary=616e646f6d73656564616e646f6d73656564616e646f6d73656564616e64
+
+<<< file0.Body
+--616e646f6d73656564616e646f6d73656564616e646f6d73656564616e64
+Content-Disposition: form-data; name="field0"; filename="file0"
+Content-Type: application/octet-stream
+
+Content of file0.
+--616e646f6d73656564616e646f6d73656564616e646f6d73656564616e64
+Content-Disposition: form-data; name="field1"
+
+value1
+--616e646f6d73656564616e646f6d73656564616e646f6d73656564616e64
+Content-Disposition: form-data; name="field1"
+
+value1.1
+--616e646f6d73656564616e646f6d73656564616e646f6d73656564616e64--