bake: additional test for print command and empty variable

Signed-off-by: CrazyMax <[email protected]>

bake/bake_test.go

@@ -2008,3 +2008,23 @@ target "app" {
 		require.Contains(t, err.Error(), "FOO must be greater than 5.")
 	})
 }
+
+// https://github.com/docker/buildx/issues/2822
+func TestVariableEmpty(t *testing.T) {
+	fp := File{
+		Name: "docker-bake.hcl",
+		Data: []byte(`
+variable "FOO" {
+  default = ""
+}
+target "app" {
+  output = [FOO]
+}
+`),
+	}
+
+	ctx := context.TODO()
+
+	_, _, err := ReadTargets(ctx, []File{fp}, []string{"app"}, nil, nil)
+	require.NoError(t, err)
+}

tests/bake.go

@@ -76,6 +76,20 @@ target "build" {
   args = {
     HELLO = "foo"
   }
+  cache-from = [
+    "type=gha,scope=build",
+    "type=s3,region=eu-west-1,bucket=mybucket",
+    "user/repo:cache",
+  ]
+  cache-to = [
+    "type=gha,scope=build,mode=max",
+    "type=s3,region=eu-west-1,bucket=mybucket",
+    "type=inline"
+  ]
+  output = [
+    "./release-out",
+    "type=registry,ref=user/app"
+  ]
 }
 `)},
 		{
@@ -104,6 +118,7 @@ RUN echo "Hello ${HELLO}"
 			)
 
 			cmd := buildxCmd(sb, withDir(dir), withArgs("bake", "--print", "build"))
+			cmd.Env = append(cmd.Env, "AWS_ACCESS_KEY_ID=foo", "AWS_SECRET_ACCESS_KEY=bar")
 			stdout := bytes.Buffer{}
 			stderr := bytes.Buffer{}
 			cmd.Stdout = &stdout
@@ -140,7 +155,21 @@ RUN echo "Hello ${HELLO}"
       "dockerfile": "Dockerfile",
       "args": {
         "HELLO": "foo"
-      }
+      },
+      "cache-from": [
+        "type=gha,scope=build",
+        "type=s3,region=eu-west-1,bucket=mybucket",
+        "type=inline"
+      ],
+      "cache-to": [
+        "type=gha,scope=build,mode=max",
+        "type=s3,region=eu-west-1,bucket=mybucket",
+        "type=inline"
+      ],
+      "output": [
+        "./release-out",
+        "type=registry,ref=user/app"
+      ]
     }
   }
 }