feat: add HTTP link checker and GitHub GraphQL repo checker

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

internal/checker/github_test.go

@@ -0,0 +1,52 @@
+package checker
+
+import (
+	"testing"
+)
+
+func TestExtractGitHubRepo(t *testing.T) {
+	tests := []struct {
+		url   string
+		owner string
+		name  string
+		ok    bool
+	}{
+		{"https://github.com/docker/compose", "docker", "compose", true},
+		{"https://github.com/moby/moby", "moby", "moby", true},
+		{"https://github.com/user/repo/", "user", "repo", true},
+		{"https://github.com/user/repo/issues", "", "", false},
+		{"https://github.com/user/repo/wiki", "", "", false},
+		{"https://github.com/apps/dependabot", "", "", false},
+		{"https://example.com/not-github", "", "", false},
+		{"https://github.com/user", "", "", false},
+	}
+
+	for _, tt := range tests {
+		owner, name, ok := ExtractGitHubRepo(tt.url)
+		if ok != tt.ok {
+			t.Errorf("ExtractGitHubRepo(%q): ok = %v, want %v", tt.url, ok, tt.ok)
+			continue
+		}
+		if ok {
+			if owner != tt.owner || name != tt.name {
+				t.Errorf("ExtractGitHubRepo(%q) = (%q, %q), want (%q, %q)", tt.url, owner, name, tt.owner, tt.name)
+			}
+		}
+	}
+}
+
+func TestPartitionLinks(t *testing.T) {
+	urls := []string{
+		"https://github.com/docker/compose",
+		"https://example.com/tool",
+		"https://github.com/moby/moby",
+		"https://github.com/user/repo/issues",
+	}
+	gh, ext := PartitionLinks(urls)
+	if len(gh) != 2 {
+		t.Errorf("github links = %d, want 2", len(gh))
+	}
+	if len(ext) != 2 {
+		t.Errorf("external links = %d, want 2", len(ext))
+	}
+}