feat(v2): Add constructors for format-specific parsers

- Add NewParser() constructors for RSS, Atom, and JSON parsers
- Update universal parser to use constructors instead of struct literals
- Remove MaxItems functionality as it was misleading (still read entire feed)
- Update all tests to use constructors

Breaking changes:
- Direct struct initialization of parsers is discouraged
- MaxItems removed from ParseOptions

Closes #248

Author: mmcdole

atom/parser.go

@@ -25,6 +25,11 @@ var (
 // Parser is an Atom Parser
 type Parser struct{}
 
+// NewParser creates a new Atom parser
+func NewParser() *Parser {
+	return &Parser{}
+}
+
 // Parse parses an xml feed into an atom.Feed
 func (ap *Parser) Parse(feed io.Reader, opts *shared.ParseOptions) (*Feed, error) {
 	p := xpp.NewXMLPullParser(feed, false, shared.NewReaderLabel)
@@ -154,12 +159,6 @@ func (ap *Parser) parseRoot(p *xpp.XMLPullParser, opts *shared.ParseOptions) (*F
 				}
 				categories = append(categories, result)
 			} else if name == "entry" {
-				// Check if we've reached the MaxItems limit
-				if opts != nil && opts.MaxItems > 0 && len(atom.Entries) >= opts.MaxItems {
-					p.Skip() // Skip this entry
-					continue
-				}
-				
 				result, err := ap.parseEntry(p)
 				if err != nil {
 					return nil, err

atom/parser_test.go

@@ -28,7 +28,7 @@ func TestParser_Parse(t *testing.T) {
 		f, _ := os.ReadFile(ff)
 
 		// Parse actual feed
-		fp := &atom.Parser{}
+		fp := atom.NewParser()
 		actual, _ := fp.Parse(bytes.NewReader(f), nil)
 
 		// Get json encoded expected feed result

internal/shared/parse_options.go

@@ -16,9 +16,6 @@ type ParseOptions struct {
 	// Parsing behavior options
 	StrictnessOptions StrictnessOptions
 
-	// Limit the number of items parsed from the feed
-	MaxItems int
-	
 	// HTTP request configuration for ParseURL
 	RequestOptions RequestOptions
 }
@@ -50,7 +47,6 @@ func DefaultParseOptions() *ParseOptions {
 			AllowMissingRequired:  true,
 			AllowUnescapedMarkup:  true,
 		},
-		MaxItems: 0, // No limit
 		RequestOptions: RequestOptions{
 			UserAgent: "gofeed/2.0 (+https://github.com/mmcdole/gofeed)",
 			Timeout:   60 * time.Second,

json/parser.go

@@ -12,6 +12,11 @@ import (
 // Parser is an JSON Feed Parser
 type Parser struct{}
 
+// NewParser creates a new JSON Feed parser
+func NewParser() *Parser {
+	return &Parser{}
+}
+
 // Parse parses an json feed into an json.Feed
 func (ap *Parser) Parse(feed io.Reader, opts *shared.ParseOptions) (*Feed, error) {
 	jsonFeed := &Feed{}
@@ -24,10 +29,5 @@ func (ap *Parser) Parse(feed io.Reader, opts *shared.ParseOptions) (*Feed, error
 		return nil, err
 	}
 
-	// Apply MaxItems limit after unmarshaling
-	if opts != nil && opts.MaxItems > 0 && len(jsonFeed.Items) > opts.MaxItems {
-		jsonFeed.Items = jsonFeed.Items[:opts.MaxItems]
-	}
-	
 	return jsonFeed, nil
 }

json/parser_test.go

@@ -34,7 +34,7 @@ func TestParser_Parse(t *testing.T) {
 		f, _ := os.ReadFile(ff)
 
 		// Parse actual feed
-		fp := &jsonParser.Parser{}
+		fp := jsonParser.NewParser()
 		actual, _ := fp.Parse(bytes.NewReader(f), nil)
 
 		// Get json encoded expected feed result
@@ -64,7 +64,7 @@ func TestParser_ParseInvalidAndStruct(t *testing.T) {
 	f, _ := os.ReadFile(ff)
 
 	// Parse actual feed
-	fp := &jsonParser.Parser{}
+	fp := jsonParser.NewParser()
 	_, err := fp.Parse(bytes.NewReader(f), nil)
 	assert.Contains(t, err.Error(), "unexpected end of JSON input")
 

parser.go

@@ -52,9 +52,9 @@ type Auth struct {
 // NewParser creates a universal feed parser.
 func NewParser() *Parser {
 	fp := Parser{
-		rp:        &rss.Parser{},
-		ap:        &atom.Parser{},
-		jp:        &json.Parser{},
+		rp:        rss.NewParser(),
+		ap:        atom.NewParser(),
+		jp:        json.NewParser(),
 	}
 	return &fp
 }

rss/parser.go

@@ -13,6 +13,11 @@ import (
 // Parser is a RSS Parser
 type Parser struct{}
 
+// NewParser creates a new RSS parser
+func NewParser() *Parser {
+	return &Parser{}
+}
+
 // Parse parses an xml feed into an rss.Feed
 func (rp *Parser) Parse(feed io.Reader, opts *shared.ParseOptions) (*Feed, error) {
 	p := xpp.NewXMLPullParser(feed, false, shared.NewReaderLabel)
@@ -66,12 +71,6 @@ func (rp *Parser) parseRoot(p *xpp.XMLPullParser, opts *shared.ParseOptions) (*F
 					return nil, err
 				}
 			} else if name == "item" {
-				// Check if we've reached the MaxItems limit
-				if opts != nil && opts.MaxItems > 0 && len(items) >= opts.MaxItems {
-					p.Skip() // Skip this item
-					continue
-				}
-				
 				item, err := rp.parseItem(p)
 				if err != nil {
 					return nil, err
@@ -254,12 +253,6 @@ func (rp *Parser) parseChannel(p *xpp.XMLPullParser, opts *shared.ParseOptions)
 				}
 				rss.SkipDays = result
 			} else if name == "item" {
-				// Check if we've reached the MaxItems limit
-				if opts != nil && opts.MaxItems > 0 && len(rss.Items) >= opts.MaxItems {
-					p.Skip() // Skip this item
-					continue
-				}
-				
 				result, err := rp.parseItem(p)
 				if err != nil {
 					return nil, err

rss/parser_test.go

@@ -26,7 +26,7 @@ func TestParser_Parse(t *testing.T) {
 		f, _ := os.ReadFile(ff)
 
 		// Parse actual feed
-		fp := &rss.Parser{}
+		fp := rss.NewParser()
 		actual, _ := fp.Parse(bytes.NewReader(f), nil)
 
 		// Get json encoded expected feed result

translator_test.go

@@ -30,7 +30,7 @@ func TestDefaultRSSTranslator_Translate(t *testing.T) {
 
 		// Parse actual feed
 		translator := &gofeed.DefaultRSSTranslator{}
-		fp := &rss.Parser{}
+		fp := rss.NewParser()
 		rssFeed, _ := fp.Parse(f, nil)
 		actual, _ := translator.Translate(rssFeed, nil)
 
@@ -72,7 +72,7 @@ func TestDefaultAtomTranslator_Translate(t *testing.T) {
 
 		// Parse actual feed
 		translator := &gofeed.DefaultAtomTranslator{}
-		fp := &atom.Parser{}
+		fp := atom.NewParser()
 		atomFeed, _ := fp.Parse(f, nil)
 		actual, _ := translator.Translate(atomFeed, nil)
 
@@ -118,7 +118,7 @@ func TestDefaultJSONTranslator_Translate(t *testing.T) {
 
 		// Parse actual feed
 		translator := &gofeed.DefaultJSONTranslator{}
-		fp := json.Parser{}
+		fp := json.NewParser()
 		jsonFeed, _ := fp.Parse(f, nil)
 		actual, _ := translator.Translate(jsonFeed, nil)
 
@@ -151,7 +151,7 @@ func TestDefaultJSONTranslator_Translate(t *testing.T) {
 
 	// Parse actual feed
 	translator := &gofeed.DefaultJSONTranslator{}
-	fp := json.Parser{}
+	fp := json.NewParser()
 	feed, _ := fp.Parse(bytes.NewReader(f), nil)
 	actual, _ := translator.Translate(feed, nil)