Add further unit tests for check rootfs format of bunnyfile

Add further unit tests for checking the unsupported features that a
rootfs field implies in a bunnyfile.
In particular add the following tests:
- Non-empty path with raw rootfs type, which means that we specify both
  a file to use as rootfs but also set the type as raw, which will
  require to unpack the file and transform it to raw. This is not
  supported yet.
- The from field equals "local" and the rootfs type is raw, which means
  that we have to use something local as raw, which is similar to the
  previous case (use a file with raw rootfs type). Again not supported
  yet.
- The from field is not scratch and we the include field is non-empty,
  which means that we want to append files in an existing rootds. This
  is not supported yet.

Signed-off-by: Charalampos Mainas <cmainas@nubificus.co.uk>

Author: cmainas

hops/validate_test.go

@@ -166,6 +166,24 @@ func TestValidateBunnyfileRootfs(t *testing.T) {
 			expectError: true,
 			errorText:   "The from field of rootfs can not be empty",
 		},
+		{
+			name:        "Invalid non-empty path, type raw",
+			input:       "local/path/raw/",
+			expectError: true,
+			errorText:   "The path field in rootfs can not be combined",
+		},
+		{
+			name:        "Invalid from local with type raw",
+			input:       "local//raw/",
+			expectError: true,
+			errorText:   "If type of rootfs is raw, then from can not",
+		},
+		{
+			name:        "Invalid from local with includes",
+			input:       "local/path//foo:bar",
+			expectError: true,
+			errorText:   "Adding files to an existing rootfs is not yet",
+		},
 		{
 			name:        "Invalid include with no source",
 			input:       "///:bar",