Start of matching rule changes

document.go

@@ -1,6 +1,7 @@
 package bkl
 
 import (
+	"github.com/gopatchy/bkl/polyfill"
 	"go.jetpack.io/typeid"
 )
 
@@ -27,13 +28,17 @@ func (d *Document) AddParents(parents ...*Document) {
 }
 
 func (d *Document) AllParents() []*Document {
-	ret := append([]*Document{}, d.Parents...)
+	parents := map[typeid.TypeID]*Document{}
 
 	for _, parent := range d.Parents {
-		ret = append(ret, parent.AllParents()...)
+		parents[parent.ID] = parent
+
+		for _, doc := range parent.AllParents() {
+			parents[doc.ID] = doc
+		}
 	}
 
-	return ret
+	return polyfill.MapsValues(parents)
 }
 
 func (d *Document) DataAsMap() map[string]any {

justfile

@@ -9,7 +9,7 @@ tidy:
 test:
 	{{go}} vet ./...
 	# golangci-lint run ./...
-	{{go}} test -race -coverprofile=cover.out -timeout=30s ./...
+	{{go}} test -race -coverprofile=cover.out -timeout=60s ./...
 	{{go}} tool cover -html=cover.out -o=cover.html
 	GOCMD={{go}} ./test
 

merge.go

@@ -29,7 +29,7 @@ func merge(dst any, src any) (any, error) {
 
 	default:
 		if src == dst {
-			return nil, fmt.Errorf("%v: %w", src, ErrUselessOverride)
+			return nil, fmt.Errorf("%#v: %w", src, ErrUselessOverride)
 		}
 
 		return src, nil

parser.go

@@ -12,6 +12,7 @@ import (
 	"os"
 
 	"github.com/gopatchy/bkl/polyfill"
+	"go.jetpack.io/typeid"
 )
 
 // A Parser reads input documents, merges layers, and generates outputs.
@@ -80,7 +81,7 @@ func (p *Parser) SetDebug(debug bool) {
 // MergeDocument applies the supplied Document to the [Parser]'s current
 // internal document state using bkl's merge semantics. If expand is true,
 // documents without $match will append; otherwise this is an error.
-func (p *Parser) MergeDocument(patch *Document, expand bool) error {
+func (p *Parser) MergeDocument(patch *Document) error {
 	matched, err := p.mergePatchMatch(patch)
 	if err != nil {
 		return err
@@ -90,17 +91,31 @@ func (p *Parser) MergeDocument(patch *Document, expand bool) error {
 		return nil
 	}
 
-	if expand {
+	docIDs := map[typeid.TypeID]bool{}
+
+	for _, doc := range p.docs {
+		docIDs[doc.ID] = true
+	}
+
+	for _, parent := range patch.AllParents() {
+		if !docIDs[parent.ID] {
+			// Parent but not in the parser's state
+			continue
+		}
+
+		matched = true
+
+		err = mergeDocs(parent, patch)
+		if err != nil {
+			return err
+		}
+	}
+
+	if !matched {
 		p.docs = append(p.docs, patch)
-		return nil
 	}
 
-	// Don't require $match when there's only one document
-	if len(p.docs) == 1 {
-		return mergeDocs(p.docs[0], patch)
-	}
-
-	return fmt.Errorf("%v: %w", patch, ErrMissingMatch)
+	return nil
 }
 
 // mergePatchMatch attempts to apply the supplied patch to one or more
@@ -172,15 +187,12 @@ func (p *Parser) MergeFileLayers(path string) error {
 // mergeFile applies an already-parsed file object into the [Parser]'s
 // document state.
 func (p *Parser) mergeFile(f *file) error {
-	// First file in an empty parser can append without $match
-	first := len(p.docs) == 0
-
 	p.log("[%s] merging", f)
 
 	for _, doc := range f.docs {
 		p.log("[%s] merging", doc)
 
-		err := p.MergeDocument(doc, first)
+		err := p.MergeDocument(doc)
 		if err != nil {
 			return fmt.Errorf("[%s:%s]: %w", f, doc, err)
 		}

parser_test.go

@@ -93,12 +93,12 @@ func ExampleParser_MergeDocument() {
 	doc2 := bkl.NewDocumentWithData(map[string]any{"b": 2})
 	doc2.AddParents(doc1)
 
-	err := b.MergeDocument(doc1, true)
+	err := b.MergeDocument(doc1)
 	if err != nil {
 		panic(err)
 	}
 
-	err = b.MergeDocument(doc2, false)
+	err = b.MergeDocument(doc2)
 	if err != nil {
 		panic(err)
 	}

polyfill/with_go1_21.go

@@ -15,10 +15,13 @@ func MapsClone[M ~map[K]V, K comparable, V any](m M) M { //nolint:ireturn
 }
 
 func MapsKeys[M ~map[K]V, K comparable, V any](m M) []K { //nolint:ireturn
-	// Added to 1.21 maps then removed again
 	return xmaps.Keys(m)
 }
 
+func MapsValues[M ~map[K]V, K comparable, V any](m M) []V { //nolint:ireturn
+	return xmaps.Values(m)
+}
+
 func SlicesClone[S ~[]E, E any](s S) S { //nolint:ireturn
 	return slices.Clone(s)
 }

polyfill/without_go1_21.go

@@ -27,6 +27,10 @@ func MapsKeys[M ~map[K]V, K comparable, V any](m M) []K { //nolint:ireturn
 	return maps.Keys(m)
 }
 
+func MapsValues[M ~map[K]V, K comparable, V any](m M) []V { //nolint:ireturn
+	return maps.Values(m)
+}
+
 // Copied from go1.21 slices
 func SlicesClone[S ~[]E, E any](s S) S { //nolint:ireturn
 	if s == nil {

tests/args/c.yaml

@@ -1,2 +1,3 @@
+$match: {}
 b: 10
 c: 3

tests/parent-skip/c.yaml

@@ -1 +1,2 @@
+$match: {}
 b: 2