fix cp bug when container exists but there are no blobs with the same prefix

Author: samtkaplan

Project.toml

@@ -1,6 +1,6 @@
 name = "AzStorage"
 uuid = "c6697862-1611-5eae-9ef8-48803c85c8d6"
-version = "2.6.3"
+version = "2.6.4"
 
 [deps]
 AbstractStorage = "14dbef02-f468-5f15-853e-5ec8dee7b899"

src/AzStorage.jl

@@ -749,7 +749,7 @@ cp(AzContainer("mycontainer";storageaccount="mystorageaccount"), "remoteblob_in.
 ```
 """
 function Base.cp(in::AbstractString, outc::AzContainer, outb::AbstractString; buffersize=2_000_000_000, show_progress=false)
-    if !isdir(outc)
+    if !iscontainer(outc)
         error("output container '$outc' does not exist. use `mkpath to create it.")
     end
 

test/runtests.jl

@@ -514,6 +514,17 @@ end
     rm("foolocal.txt")
 end
 
+@testset "Container, copy local file to blob, with prefix" begin
+    write("foolocal.txt", "Hello world")
+    r = uuid4()
+    c = AzContainer("one/two/three/four/foo-$r-o", storageaccount=storageaccount, session=session, nthreads=2, nretry=10)
+    robust_mkpath(c)
+    cp("foolocal.txt", c, "foo.txt")
+    @test read(c, "foo.txt", String) == "Hello world"
+    rm(c)
+    rm("foolocal.txt")
+end
+
 @testset "Container, copy large local file to blob" begin
     n = 100
     x = rand(UInt8, n)