Merge pull request #34 from buildkite/comp-352-agent-re-writes-pipeli…

…ne-with-remaining-fields-inserted-into

Add Name and Size fields to Cache - COMP-352

step_command_cache.go

@@ -1,30 +1,50 @@
 package pipeline
 
 import (
+	"encoding/json"
 	"fmt"
 
 	"github.com/buildkite/go-pipeline/ordered"
 )
 
-var _ ordered.Unmarshaler = (*Cache)(nil)
+var _ interface {
+	json.Marshaler
+	ordered.Unmarshaler
+} = (*Cache)(nil)
 
 var (
 	errUnsupportedCacheType = fmt.Errorf("unsupported type for cache")
 )
 
 // Cache models the cache settings for a given step
 type Cache struct {
-	Paths []string `json:"paths" yaml:"paths"`
+	Disabled bool     `yaml:",omitempty"`
+	Name     string   `yaml:"name,omitempty"`
+	Paths    []string `yaml:"paths,omitempty"`
+	Size     string   `yaml:"size,omitempty"`
 
 	RemainingFields map[string]any `yaml:",inline"`
 }
 
+// MarshalJSON marshals the step to JSON. Special handling is needed because
+// yaml.v3 has "inline" but encoding/json has no concept of it.
+func (c *Cache) MarshalJSON() ([]byte, error) {
+	if c.Disabled {
+		return json.Marshal(false)
+	}
+	return inlineFriendlyMarshalJSON(c)
+}
+
 // UnmarshalOrdered unmarshals from the following types:
 // - string: a single path
 // - []string: multiple paths
 // - ordered.Map: a map containing paths, among potentially other things
 func (c *Cache) UnmarshalOrdered(o any) error {
 	switch v := o.(type) {
+	case bool:
+		if !v {
+			c.Disabled = true
+		}
 	case string:
 		c.Paths = []string{v}
 

step_command_cache_test.go

@@ -8,6 +8,71 @@ import (
 	"github.com/google/go-cmp/cmp"
 )
 
+func TestCacheMarshalJSON(t *testing.T) {
+	t.Parallel()
+
+	cases := []struct {
+		name string
+		c    Cache
+		want string
+	}{
+		{
+			name: "single path",
+			c:    Cache{Paths: []string{"path/to/cache"}},
+			want: `{"paths":["path/to/cache"]}`,
+		},
+		{
+			name: "multiple paths",
+			c:    Cache{Paths: []string{"path/to/cache", "another/path"}},
+			want: `{"paths":["path/to/cache","another/path"]}`,
+		},
+		{
+			name: "empty cache settings block",
+			c:    Cache{},
+			want: `{}`,
+		},
+		{
+			name: "full cache settings block",
+			c: Cache{
+				Paths: []string{"path/to/cache", "another/path"},
+				Name:  "cache-name",
+				Size:  "25g",
+			},
+			want: `{"name":"cache-name","paths":["path/to/cache","another/path"],"size":"25g"}`,
+		},
+		{
+			name: "full cache settings block with extra fields",
+			c: Cache{
+				Paths:           []string{"path/to/cache", "another/path"},
+				Name:            "cache-name",
+				Size:            "25g",
+				RemainingFields: map[string]any{"extra": "field"},
+			},
+			want: `{"extra":"field","name":"cache-name","paths":["path/to/cache","another/path"],"size":"25g"}`,
+		},
+		{
+			name: "disabled cache",
+			c:    Cache{Disabled: true},
+			want: `false`,
+		},
+	}
+
+	for _, tc := range cases {
+		t.Run(tc.name, func(t *testing.T) {
+			t.Parallel()
+
+			b, err := tc.c.MarshalJSON()
+			if err != nil {
+				t.Fatalf("Cache.MarshalJSON() error: %v", err)
+			}
+
+			if diff := cmp.Diff(string(b), tc.want); diff != "" {
+				t.Errorf("Cache.MarshalJSON() diff (-got +want):\n%s", diff)
+			}
+		})
+	}
+}
+
 func TestCacheUnmarshalOrdered(t *testing.T) {
 	t.Parallel()
 
@@ -31,17 +96,23 @@ func TestCacheUnmarshalOrdered(t *testing.T) {
 			name: "full cache settings block",
 			input: ordered.MapFromItems(
 				ordered.TupleSA{Key: "paths", Value: []any{"path/to/cache", "another/path"}},
+				ordered.TupleSA{Key: "name", Value: "cache-name"},
+				ordered.TupleSA{Key: "size", Value: "25g"},
 			),
-			want: Cache{Paths: []string{"path/to/cache", "another/path"}},
+			want: Cache{Paths: []string{"path/to/cache", "another/path"}, Name: "cache-name", Size: "25g"},
 		},
 		{
 			name: "full cache settings block with extra fields",
 			input: ordered.MapFromItems(
 				ordered.TupleSA{Key: "paths", Value: []any{"path/to/cache", "another/path"}},
+				ordered.TupleSA{Key: "name", Value: "cache-name"},
+				ordered.TupleSA{Key: "size", Value: "25g"},
 				ordered.TupleSA{Key: "extra", Value: "field"},
 			),
 			want: Cache{
 				Paths:           []string{"path/to/cache", "another/path"},
+				Name:            "cache-name",
+				Size:            "25g",
 				RemainingFields: map[string]any{"extra": "field"},
 			},
 		},