feat: guidelines

internal/pierre/guidelines_test.go

@@ -0,0 +1,70 @@
+package pierre
+
+import (
+	"fmt"
+	"strings"
+	"testing"
+)
+
+func TestParseGuidelinesFromStringValid(t *testing.T) {
+	md := "# Rule One\n\n  - Item A  \n\n# Rule Two\n"
+	lines, err := parseGuidelinesFromString(md)
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	expected := []string{"# Rule One", "- Item A", "# Rule Two"}
+	if got, want := fmt.Sprint(lines), fmt.Sprint(expected); got != want {
+		t.Fatalf("expected %v, got %v", expected, lines)
+	}
+}
+
+func TestParseGuidelinesFromStringEmpty(t *testing.T) {
+	md := "\n   \n"
+	lines, err := parseGuidelinesFromString(md)
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	if len(lines) != 0 {
+		t.Fatalf("expected empty slice, got %d elements", len(lines))
+	}
+}
+
+func TestParseGuidelinesFromStringTooManyLines(t *testing.T) {
+	// generate 1001 non-empty lines
+	var sb strings.Builder
+	for i := 0; i < 1001; i++ {
+		sb.WriteString(fmt.Sprintf("Line %d\n", i))
+	}
+	_, err := parseGuidelinesFromString(sb.String())
+	if err == nil {
+		t.Fatalf("expected error for exceeding line limit, got nil")
+	}
+}
+
+func TestWithGuidelinesSuccess(t *testing.T) {
+	svc := &Service{}
+	md := "First line\nSecond line\n"
+	if err := svc.WithGuidelines(md); err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	expected := []string{"First line", "Second line"}
+	if got, want := fmt.Sprint(svc.guidelines), fmt.Sprint(expected); got != want {
+		t.Fatalf("expected guidelines %v, got %v", expected, svc.guidelines)
+	}
+}
+
+func TestWithGuidelinesError(t *testing.T) {
+	svc := &Service{guidelines: []string{"old"}}
+	var sb strings.Builder
+	for i := 0; i < 1001; i++ {
+		sb.WriteString("x\n")
+	}
+	err := svc.WithGuidelines(sb.String())
+	if err == nil {
+		t.Fatalf("expected error, got nil")
+	}
+	// ensure old guidelines unchanged
+	if len(svc.guidelines) != 1 || svc.guidelines[0] != "old" {
+		t.Fatalf("guidelines should remain unchanged on error")
+	}
+}

internal/pierre/resource.go

@@ -2,7 +2,9 @@ package pierre
 
 import (
 	"context"
+	"fmt"
 	"io"
+	"strings"
 
 	"git.schreifuchs.ch/schreifuchs/pierre-bot/internal/chatter"
 )
@@ -14,13 +16,14 @@ import (
 // elsewhere in the future.
 type Service struct {
 	maxChunkSize    int
-	guidelines      []string
+	guidelines      []string // stored as slice of lines; legacy, see WithGuidelines
 	disableComments bool
 	git             GitAdapter
 	chat            ChatAdapter
 }
 
 func New(chat ChatAdapter, git GitAdapter, maxChunkSize int, guidelines []string, disableComments bool) *Service {
+	// Existing constructor retains slice based guidelines for backward compatibility.
 	return &Service{
 		git:             git,
 		chat:            chat,
@@ -30,6 +33,39 @@ func New(chat ChatAdapter, git GitAdapter, maxChunkSize int, guidelines []string
 	}
 }
 
+// WithGuidelines parses a raw Markdown string (or any multiline string) into
+// individual guideline lines, validates the line‑count (max 1000 non‑empty lines),
+// and stores the result in the Service. It returns an error if validation fails.
+// This is a convenience mutator for callers that have the guidelines as a
+// single string.
+func (s *Service) WithGuidelines(md string) error {
+	lines, err := parseGuidelinesFromString(md)
+	if err != nil {
+		return err
+	}
+	s.guidelines = lines
+	return nil
+}
+
+// parseGuidelinesFromString splits a markdown string into trimmed, non‑empty
+// lines and ensures the total number of lines does not exceed 1000.
+func parseGuidelinesFromString(md string) ([]string, error) {
+	var result []string
+	// Split on newline. Handles both \n and \r\n because TrimSpace removes \r.
+	rawLines := strings.Split(md, "\n")
+	for _, l := range rawLines {
+		trimmed := strings.TrimSpace(l)
+		if trimmed == "" {
+			continue
+		}
+		result = append(result, trimmed)
+	}
+	if len(result) > 1000 {
+		return nil, fmt.Errorf("guidelines exceed 1000 lines (found %d)", len(result))
+	}
+	return result, nil
+}
+
 type GitAdapter interface {
 	GetDiff(ctx context.Context, owner, repo string, prID int) (io.ReadCloser, error)
 	AddComment(ctx context.Context, owner, repo string, prID int, comment Comment) error