bake: support composable attributes

Signed-off-by: CrazyMax <1951866+crazy-max@users.noreply.github.com>

__tests__/.fixtures/bake-01-overrides.json

@@ -22,7 +22,9 @@
         "linux/amd64"
       ],
       "output": [
-        "type=docker"
+        {
+          "type": "docker"
+        }
       ]
     }
   }

__tests__/.fixtures/bake-01-validate.json

@@ -22,7 +22,9 @@
         "GO_VERSION": "1.20"
       },
       "output": [
-        "type=cacheonly"
+        {
+          "type": "cacheonly"
+        }
       ]
     },
     "validate-docs": {
@@ -36,7 +38,9 @@
       },
       "target": "validate",
       "output": [
-        "type=cacheonly"
+        {
+          "type": "cacheonly"
+        }
       ]
     },
     "validate-vendor": {
@@ -48,7 +52,9 @@
       },
       "target": "validate",
       "output": [
-        "type=cacheonly"
+        {
+          "type": "cacheonly"
+        }
       ]
     }
   }

__tests__/.fixtures/bake-03-default.json

@@ -0,0 +1,38 @@
+{
+  "target": {
+    "default": {
+      "context": ".",
+      "dockerfile": "Dockerfile",
+      "cache-from": [
+        {
+          "scope": "build",
+          "type": "gha"
+        },
+        {
+          "ref": "user/repo:cache",
+          "type": "registry"
+        }
+      ],
+      "cache-to": [
+        {
+          "mode": "max",
+          "scope": "build",
+          "type": "gha"
+        },
+        {
+          "type": "inline"
+        }
+      ],
+      "output": [
+        {
+          "dest": "./release-out",
+          "type": "local"
+        },
+        {
+          "ref": "user/app",
+          "type": "registry"
+        }
+      ]
+    }
+  }
+}

__tests__/.fixtures/bake-03.hcl

@@ -0,0 +1,28 @@
+// Copyright 2024 actions-toolkit authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+target "default" {
+  cache-from = [
+    "type=gha,scope=build",
+    "user/repo:cache",
+  ]
+  cache-to = [
+    "type=gha,scope=build,mode=max",
+    "type=inline"
+  ]
+  output = [
+    "./release-out",
+    "type=registry,ref=user/app"
+  ]
+}

__tests__/.fixtures/bake-buildx-0.10.4-binaries-cross.json

@@ -29,7 +29,10 @@
         "windows/arm64"
       ],
       "output": [
-        "./bin/build"
+        {
+          "dest": "./bin/build",
+          "type": "local"
+        }
       ]
     }
   }