test: improved test coverage

* refactored to remove unreachable (untestable) code
* added tests for edge cases

Signed-off-by: Frédéric BIDON <fredbi@yahoo.com>

Author: fredbi

pointer.go

@@ -166,33 +166,36 @@ func (p *Pointer) set(node, data any, nameProvider *jsonname.NameProvider) error
 		)
 	}
 
+	l := len(p.referenceTokens)
+
 	// full document when empty
-	if len(p.referenceTokens) == 0 {
+	if l == 0 {
 		return nil
 	}
 
 	if nameProvider == nil {
 		nameProvider = jsonname.DefaultJSONNameProvider
 	}
 
-	lastI := len(p.referenceTokens) - 1
-	for i, token := range p.referenceTokens {
-		isLastToken := i == lastI
-		decodedToken := Unescape(token)
+	var decodedToken string
+	lastIndex := l - 1
 
-		if isLastToken {
-			return setSingleImpl(node, data, decodedToken, nameProvider)
-		}
+	if lastIndex > 0 { // skip if we only have one token in pointer
+		for _, token := range p.referenceTokens[:lastIndex] {
+			decodedToken = Unescape(token)
+			next, err := p.resolveNodeForToken(node, decodedToken, nameProvider)
+			if err != nil {
+				return err
+			}
 
-		next, err := p.resolveNodeForToken(node, decodedToken, nameProvider)
-		if err != nil {
-			return err
+			node = next
 		}
-
-		node = next
 	}
 
-	return nil
+	// last token
+	decodedToken = Unescape(p.referenceTokens[lastIndex])
+
+	return setSingleImpl(node, data, decodedToken, nameProvider)
 }
 
 func (p *Pointer) resolveNodeForToken(node any, decodedToken string, nameProvider *jsonname.NameProvider) (next any, err error) {

pointer_test.go

@@ -114,6 +114,7 @@ func TestFullDocument(t *testing.T) {
 				require.True(t, ok)
 
 				asArray, ok := foos.([]any)
+				require.True(t, ok)
 				require.Len(t, asArray, 2)
 
 				foo := asArray[0]