refactor(tests): group test files by feature, drop phase/cluster naming

Restructures the integration test layout so each file is named after
what it covers, not the implementation phase it landed in.

nuwiki-core (renames only):
  vimwiki_lexer            → lexer
  vimwiki_parser           → parser
  vimwiki_tags             → tags
  vimwiki_table_alignment  → table_alignment
  diary_period             → diary
  list_continuation        → lists
  transclusion_attrs       → transclusion
  + table colspan/rowspan tests moved here from parity_cluster_1

nuwiki-lsp (renames + merges + one split):
  cluster_a_list_rewriters       → commands_lists
  cluster_b_table_rewriters      → commands_tables
  cluster_c_link_helpers +
    phase19_followlink_creates   → commands_links
  phase13_rename_commands        → commands_files
  phase17_colorize               → commands_colorize
  phase17_html_export            → html_export
  phase15_link_health            → link_health
  phase18_multi_wiki             → multi_wiki
  phase19_folding                → folding
  nav                            → navigation
  lsp_helpers                    → helpers
  phase16_diary +
    diary_frequency              → diary
  phase11_plumbing +
    parity_cluster_1 (config)    → index_and_config
  tags_index_and_lsp +
    phase17_backfill             → commands_tags
  phase14_edit_commands          → split into
    commands_checkboxes,
    commands_headings,
    commands_tasks

Net: 30 → 28 integration-test files. 456 → 455 tests (the one
removed test was a dummy `paragraph_render_is_unchanged` whose only
purpose was to keep a `ParagraphNode` import alive in
parity_cluster_1; the import is exercised elsewhere now).

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

crates/nuwiki-lsp/tests/navigation.rs

@@ -0,0 +1,228 @@
+//! Tests for the Phase 8 navigation pieces: WorkspaceIndex queries,
+//! page-name derivation, anchor slugify, position lookup, and link
+//! resolution. The async LSP handlers are exercised through these
+//! helpers; end-to-end JSON-RPC drive lives in a follow-up phase.
+
+use std::path::PathBuf;
+
+use nuwiki_core::ast::{InlineNode, LinkKind};
+use nuwiki_core::syntax::vimwiki::VimwikiSyntax;
+use nuwiki_core::syntax::SyntaxPlugin;
+use nuwiki_lsp::index::{page_name_from_uri, slugify, WorkspaceIndex};
+use nuwiki_lsp::nav::{find_inline_at, lsp_to_byte_pos};
+use tower_lsp::lsp_types::{Position as LspPosition, Url};
+
+fn parse(src: &str) -> nuwiki_core::ast::DocumentNode {
+    VimwikiSyntax::new().parse(src)
+}
+
+// ===== Slugify =====
+
+#[test]
+fn slugify_basic_title() {
+    assert_eq!(slugify("Hello World"), "hello-world");
+}
+
+#[test]
+fn slugify_strips_punctuation_and_collapses_dashes() {
+    assert_eq!(slugify("Hello, World!  Again"), "hello-world-again");
+}
+
+#[test]
+fn slugify_unicode_lowercase() {
+    assert_eq!(slugify("Crème Brûlée"), "crème-brûlée");
+}
+
+#[test]
+fn slugify_no_trailing_dash() {
+    assert_eq!(slugify("Title — "), "title");
+}
+
+// ===== Page name from URI =====
+
+#[test]
+fn page_name_relative_to_root() {
+    let root = PathBuf::from("/wiki");
+    let uri = Url::from_file_path("/wiki/dir/Page.wiki").unwrap();
+    assert_eq!(page_name_from_uri(&uri, Some(&root)), "dir/Page");
+}
+
+#[test]
+fn page_name_at_root() {
+    let root = PathBuf::from("/wiki");
+    let uri = Url::from_file_path("/wiki/Index.wiki").unwrap();
+    assert_eq!(page_name_from_uri(&uri, Some(&root)), "Index");
+}
+
+#[test]
+fn page_name_without_root_falls_back_to_stem() {
+    let uri = Url::from_file_path("/tmp/foo.wiki").unwrap();
+    assert_eq!(page_name_from_uri(&uri, None), "foo");
+}
+
+// ===== Workspace index =====
+
+#[test]
+fn upsert_indexes_headings_and_outgoing_links() {
+    let mut idx = WorkspaceIndex::new(Some(PathBuf::from("/wiki")));
+    let uri = Url::from_file_path("/wiki/Home.wiki").unwrap();
+    let ast = parse("= Home =\n[[Other]] and [[#Section]]\n");
+    idx.upsert(uri.clone(), &ast);
+
+    let page = idx.page(&uri).expect("page indexed");
+    assert_eq!(page.name, "Home");
+    assert_eq!(page.headings.len(), 1);
+    assert_eq!(page.headings[0].title, "Home");
+    assert_eq!(page.headings[0].anchor, "home");
+    assert_eq!(page.outgoing.len(), 2);
+    assert_eq!(page.outgoing[0].target_page.as_deref(), Some("Other"));
+    assert_eq!(page.outgoing[0].kind, LinkKind::Wiki);
+    assert_eq!(page.outgoing[1].kind, LinkKind::AnchorOnly);
+}
+
+#[test]
+fn upsert_registers_page_by_name_and_records_backlinks() {
+    let mut idx = WorkspaceIndex::new(Some(PathBuf::from("/wiki")));
+    let home = Url::from_file_path("/wiki/Home.wiki").unwrap();
+    let about = Url::from_file_path("/wiki/About.wiki").unwrap();
+
+    idx.upsert(home.clone(), &parse("[[About]]\n"));
+    idx.upsert(about.clone(), &parse("= About =\n"));
+
+    assert_eq!(idx.page_by_name("About").unwrap().uri, about);
+
+    let backlinks = idx.backlinks_for("About");
+    assert_eq!(backlinks.len(), 1);
+    assert_eq!(backlinks[0].source_uri, home);
+}
+
+#[test]
+fn upsert_replaces_prior_indexing_for_same_uri() {
+    let mut idx = WorkspaceIndex::new(Some(PathBuf::from("/wiki")));
+    let uri = Url::from_file_path("/wiki/Home.wiki").unwrap();
+    idx.upsert(uri.clone(), &parse("[[A]]\n"));
+    assert_eq!(idx.backlinks_for("A").len(), 1);
+
+    // Re-upsert with different content: old backlinks must drop.
+    idx.upsert(uri.clone(), &parse("[[B]]\n"));
+    assert_eq!(idx.backlinks_for("A").len(), 0);
+    assert_eq!(idx.backlinks_for("B").len(), 1);
+}
+
+#[test]
+fn remove_drops_page_and_backlinks() {
+    let mut idx = WorkspaceIndex::new(Some(PathBuf::from("/wiki")));
+    let home = Url::from_file_path("/wiki/Home.wiki").unwrap();
+    let about = Url::from_file_path("/wiki/About.wiki").unwrap();
+    idx.upsert(home.clone(), &parse("[[About]]\n"));
+    idx.upsert(about.clone(), &parse("= About =\n"));
+
+    idx.remove(&home);
+    assert!(idx.page(&home).is_none());
+    assert!(idx.backlinks_for("About").is_empty());
+    // The target page is untouched.
+    assert!(idx.page(&about).is_some());
+}
+
+#[test]
+fn resolve_wiki_link_to_uri() {
+    let mut idx = WorkspaceIndex::new(Some(PathBuf::from("/wiki")));
+    let about = Url::from_file_path("/wiki/About.wiki").unwrap();
+    idx.upsert(about.clone(), &parse("= About =\n"));
+
+    let target = nuwiki_core::ast::LinkTarget {
+        kind: LinkKind::Wiki,
+        path: Some("About".into()),
+        ..Default::default()
+    };
+    assert_eq!(idx.resolve(&target, "Home"), Some(&about));
+}
+
+#[test]
+fn resolve_anchor_only_link_returns_source_page() {
+    let mut idx = WorkspaceIndex::new(Some(PathBuf::from("/wiki")));
+    let home = Url::from_file_path("/wiki/Home.wiki").unwrap();
+    idx.upsert(home.clone(), &parse("= H =\n[[#Section]]\n"));
+
+    let target = nuwiki_core::ast::LinkTarget {
+        kind: LinkKind::AnchorOnly,
+        anchor: Some("section".into()),
+        ..Default::default()
+    };
+    assert_eq!(idx.resolve(&target, "Home"), Some(&home));
+}
+
+#[test]
+fn page_names_lists_indexed_pages_sorted() {
+    let mut idx = WorkspaceIndex::new(Some(PathBuf::from("/wiki")));
+    for name in ["Charlie", "Alpha", "Bravo"] {
+        let uri = Url::from_file_path(format!("/wiki/{name}.wiki")).unwrap();
+        idx.upsert(uri, &parse(&format!("= {name} =\n")));
+    }
+    let names = idx.page_names();
+    assert_eq!(names, vec!["Alpha", "Bravo", "Charlie"]);
+}
+
+// ===== Position conversion =====
+
+#[test]
+fn lsp_to_byte_pos_passthrough_in_utf8() {
+    let p = LspPosition {
+        line: 2,
+        character: 5,
+    };
+    let (line, col) = lsp_to_byte_pos(p, "ignored", true);
+    assert_eq!((line, col), (2, 5));
+}
+
+#[test]
+fn lsp_to_byte_pos_converts_from_utf16() {
+    // 'é' is one UTF-16 code unit, two UTF-8 bytes. Char "2" after 'é':
+    // UTF-16 col 2 → byte col 3.
+    let text = "héllo\n";
+    let p = LspPosition {
+        line: 0,
+        character: 2,
+    };
+    let (line, col) = lsp_to_byte_pos(p, text, false);
+    assert_eq!(line, 0);
+    assert_eq!(col, 3);
+}
+
+// ===== Position lookup =====
+
+#[test]
+fn find_inline_at_returns_wikilink_under_cursor() {
+    let src = "see [[Other]] now\n";
+    let doc = parse(src);
+    // Cursor inside "Other" — byte col 6 falls inside "[[Other]]" (which
+    // starts at byte 4 and ends at byte 13).
+    let node = find_inline_at(&doc, 0, 6).expect("wikilink at cursor");
+    assert!(matches!(node, InlineNode::WikiLink(_)));
+}
+
+#[test]
+fn find_inline_at_returns_none_for_plain_text() {
+    let src = "just text\n";
+    let doc = parse(src);
+    let node = find_inline_at(&doc, 0, 3);
+    // "just text" → Text node, which is what we get back from the inner
+    // walk (not None). Verify it's a Text.
+    assert!(matches!(node, Some(InlineNode::Text(_))));
+}
+
+#[test]
+fn find_inline_at_descends_into_inline_containers() {
+    let src = "*bold text*\n";
+    let doc = parse(src);
+    // Inside "bold" — should return the inner Text, not the wrapping Bold.
+    let node = find_inline_at(&doc, 0, 3).expect("hit");
+    assert!(matches!(node, InlineNode::Text(_)));
+}
+
+#[test]
+fn find_inline_at_returns_none_past_eol() {
+    let src = "short\n";
+    let doc = parse(src);
+    assert!(find_inline_at(&doc, 0, 999).is_none());
+}