ast: remove 'parse if id key is in metadata' heuristic

Since we process annotations by default now, this is no longer relevant.
Users that opt-out of annotations processing will not benefit from rule
IDs _in metadata_, but that's consistent.

Signed-off-by: Stephan Renatus <stephan.renatus@gmail.com>

Author: srenatus

CHANGELOG.md

@@ -32,7 +32,6 @@ Duplicate IDs from functions called multiple times are suppressed.
 allow if input.role == "admin"
 ```
 
-Modules containing `id` annotations will have metadata parsing enabled automatically.
 When external rule sources are registered, rule tracking is always enabled so that
 externally-provided rules with `id` annotations are recorded.
 

v1/ast/parser.go

@@ -545,30 +545,13 @@ func (p *Parser) Parse() ([]Statement, []*Comment, Errors) {
 		break
 	}
 
-	if !p.po.ProcessAnnotation && hasMetadataWithID(p.s.comments) {
-		p.po.ProcessAnnotation = true
-	}
-
 	if p.po.ProcessAnnotation {
 		stmts = p.parseAnnotations(stmts)
 	}
 
 	return stmts, p.s.comments, p.s.errors
 }
 
-func hasMetadataWithID(comments []*Comment) bool {
-	for i := range comments {
-		if IsMetadataComment(comments[i]) {
-			for i++; i < len(comments) && !blockBuster(comments[i], comments[i-1]); i++ {
-				if bytes.HasPrefix(bytes.TrimSpace(comments[i].Text), []byte("id:")) {
-					return true
-				}
-			}
-		}
-	}
-	return false
-}
-
 func (p *Parser) parseAnnotations(stmts []Statement) []Statement {
 	annotStmts, errs := parseAnnotations(p.s.comments)
 	for _, err := range errs {

v1/ast/parser_test.go

@@ -8197,61 +8197,6 @@ allow if {
 	assertLocationText(t, "# METADATA\n# title: rule", m.Rules[0].Annotations[0].Location)
 }
 
-func TestAnnotationsAutoEnableWithID(t *testing.T) {
-	tests := []struct {
-		note                string
-		module              string
-		processAnnotation   bool
-		expAnnotationsCount int
-	}{
-		{
-			note: "auto-enable when metadata has id field",
-			module: `package test
-# METADATA
-# id: test-rule
-allow if true
-`,
-			processAnnotation:   false,
-			expAnnotationsCount: 1,
-		},
-		{
-			note: "no auto-enable when metadata lacks id field",
-			module: `# METADATA
-# title: Test Rule
-package test
-allow if true
-`,
-			processAnnotation:   false,
-			expAnnotationsCount: 0,
-		},
-		{
-			note: "explicit ProcessAnnotation still works",
-			module: `# METADATA
-# title: Test Rule
-package test
-allow if true
-`,
-			processAnnotation:   true,
-			expAnnotationsCount: 1,
-		},
-	}
-
-	for _, tc := range tests {
-		t.Run(tc.note, func(t *testing.T) {
-			m, err := ParseModuleWithOpts("test.rego", tc.module, ParserOptions{
-				ProcessAnnotation: tc.processAnnotation,
-			})
-			if err != nil {
-				t.Fatal(err)
-			}
-
-			if len(m.Annotations) != tc.expAnnotationsCount {
-				t.Errorf("expected %d annotations but got %d", tc.expAnnotationsCount, len(m.Annotations))
-			}
-		})
-	}
-}
-
 func TestMaxParsingRecursionDepth(t *testing.T) {
 	tests := []struct {
 		name        string