Add test from memory source

Author: rolandlo

spec/connection_spec.lua

@@ -2,23 +2,42 @@ local vips = require "vips"
 local ffi = require "ffi"
 
 local JPEG_FILE = "./spec/images/Gugg_coloured.jpg"
--- test gvalue
-describe("test connection", function()
+local TMP_FILE = ffi.os == "Windows" and os.getenv("TMP") .. "\\x.png" or "/tmp/x.png"
 
+describe("test connection", function()
     setup(function()
         -- vips.log.enable(true)
     end)
 
     describe("to file target", function()
-        it("can create image from file source and write to file target", function()
+        local target
+
+        setup(function()
+            target = vips.Target.new_to_file(TMP_FILE)
+        end)
+
+        it("can create image from file source", function()
             local source = vips.Source.new_from_file(JPEG_FILE)
             local image = vips.Image.new_from_source(source, '', { access = 'sequential' })
-            local filename = ffi.os == "Windows" and os.getenv("TMP") .. "\\x.png" or "/tmp/x.png"
-            local target = vips.Target.new_to_file(filename)
             image:write_to_target(target, '.png')
 
             local image1 = vips.Image.new_from_file(JPEG_FILE, { access = 'sequential' })
-            local image2 = vips.Image.new_from_file(filename, { access = 'sequential' })
+            local image2 = vips.Image.new_from_file(TMP_FILE, { access = 'sequential' })
+            assert.is_true((image1 - image2):abs():max() < 10)
+        end)
+
+        it("can create image from memory source", function()
+            local file = assert(io.open(JPEG_FILE, "rb"))
+            local content = file:read("*a")
+            file:close()
+            local mem = ffi.new("unsigned char[?]", #content)
+            ffi.copy(mem, content, #content)
+            local source = vips.Source.new_from_memory(mem)
+            local image = vips.Image.new_from_source(source, '', { access = 'sequential' })
+            image:write_to_target(target, '.png')
+
+            local image1 = vips.Image.new_from_file(JPEG_FILE, { access = 'sequential' })
+            local image2 = vips.Image.new_from_file(TMP_FILE, { access = 'sequential' })
             assert.is_true((image1 - image2):abs():max() < 10)
         end)
     end)

src/vips/Source.lua

@@ -27,7 +27,7 @@ Source.new_from_file = function(filename)
     return Connection.new(source)
 end
 
-Source.new_from_memory = function(data) -- data is an FFI memory array formatted as a C-style array
+Source.new_from_memory = function(data) -- data is an FFI memory array containing the image data
     local source = vips_lib.vips_source_new_from_memory(data, ffi.sizeof(data))
     if source == ffi.NULL then
         error("Can't create input source from memory \n" .. verror.get())