nuwiki/crates/nuwiki-core/tests/visitor.rs

//! Smoke test for the AST visitor: build a small document by hand and
//! confirm a Visitor descends into every nested node exactly once.

use std::collections::HashMap;

use nuwiki_core::ast::{
    BlockNode, BoldNode, DocumentNode, ExternalLinkNode, HeadingNode, InlineNode, ListItemNode,
    ListNode, ListSymbol, ParagraphNode, Span, TableCellNode, TableNode, TableRowNode, TextNode,
    TransclusionNode, Visitor,
};

#[derive(Default)]
struct Counter {
    headings: usize,
    paragraphs: usize,
    text: usize,
    bold: usize,
    list_items: usize,
    table_cells: usize,
    external_links: usize,
    transclusions: usize,
    blocks: usize,
    inlines: usize,
}

impl Visitor for Counter {
    fn visit_block(&mut self, node: &BlockNode) {
        self.blocks += 1;
        nuwiki_core::ast::walk_block(self, node);
    }
    fn visit_inline(&mut self, node: &InlineNode) {
        self.inlines += 1;
        nuwiki_core::ast::walk_inline(self, node);
    }
    fn visit_heading(&mut self, node: &HeadingNode) {
        self.headings += 1;
        for child in &node.children {
            self.visit_inline(child);
        }
    }
    fn visit_paragraph(&mut self, node: &ParagraphNode) {
        self.paragraphs += 1;
        for child in &node.children {
            self.visit_inline(child);
        }
    }
    fn visit_text(&mut self, _: &TextNode) {
        self.text += 1;
    }
    fn visit_bold(&mut self, node: &BoldNode) {
        self.bold += 1;
        for child in &node.children {
            self.visit_inline(child);
        }
    }
    fn visit_list_item(&mut self, node: &ListItemNode) {
        self.list_items += 1;
        nuwiki_core::ast::walk_list_item(self, node);
    }
    fn visit_table_cell(&mut self, node: &TableCellNode) {
        self.table_cells += 1;
        for child in &node.children {
            self.visit_inline(child);
        }
    }
    fn visit_external_link(&mut self, node: &ExternalLinkNode) {
        self.external_links += 1;
        if let Some(desc) = &node.description {
            for child in desc {
                self.visit_inline(child);
            }
        }
    }
    fn visit_transclusion(&mut self, _: &TransclusionNode) {
        self.transclusions += 1;
    }
}

fn text(s: &str) -> InlineNode {
    InlineNode::Text(TextNode {
        span: Span::default(),
        content: s.into(),
    })
}

#[test]
fn visitor_descends_into_every_node() {
    // = Title with *bold* word =
    let heading = BlockNode::Heading(HeadingNode {
        span: Span::default(),
        level: 1,
        centered: false,
        children: vec![
            text("Title with "),
            InlineNode::Bold(BoldNode {
                span: Span::default(),
                children: vec![text("bold")],
            }),
            text(" word"),
        ],
    });

    // A paragraph containing an external link with two text children in its
    // description, and a transclusion sibling.
    let paragraph = BlockNode::Paragraph(ParagraphNode {
        span: Span::default(),
        children: vec![
            InlineNode::ExternalLink(ExternalLinkNode {
                span: Span::default(),
                url: "https://example.com".into(),
                description: Some(vec![text("see "), text("docs")]),
            }),
            InlineNode::Transclusion(TransclusionNode {
                span: Span::default(),
                url: "image.png".into(),
                alt: None,
                attrs: HashMap::new(),
            }),
        ],
    });

    // - one
    // - two
    let list = BlockNode::List(ListNode {
        span: Span::default(),
        ordered: false,
        symbol: ListSymbol::Dash,
        items: vec![
            ListItemNode {
                span: Span::default(),
                symbol: ListSymbol::Dash,
                level: 0,
                checkbox: None,
                children: vec![text("one")],
                sublist: None,
            },
            ListItemNode {
                span: Span::default(),
                symbol: ListSymbol::Dash,
                level: 0,
                checkbox: None,
                children: vec![text("two")],
                sublist: None,
            },
        ],
    });

    // | a | b |
    let table = BlockNode::Table(TableNode {
        span: Span::default(),
        has_header: false,
        alignments: Vec::new(),
        rows: vec![TableRowNode {
            span: Span::default(),
            is_header: false,
            cells: vec![
                TableCellNode {
                    span: Span::default(),
                    children: vec![text("a")],
                    col_span: false,
                    row_span: false,
                },
                TableCellNode {
                    span: Span::default(),
                    children: vec![text("b")],
                    col_span: false,
                    row_span: false,
                },
            ],
        }],
    });

    let doc = DocumentNode {
        span: Span::default(),
        metadata: Default::default(),
        children: vec![heading, paragraph, list, table],
    };

    let mut counter = Counter::default();
    counter.visit_document(&doc);

    // Block-level: 4 top-level + 2 list items aren't blocks
    assert_eq!(counter.blocks, 4, "top-level blocks");
    assert_eq!(counter.headings, 1);
    assert_eq!(counter.paragraphs, 1);
    assert_eq!(counter.list_items, 2);
    // 1 cell row with 2 cells
    assert_eq!(counter.table_cells, 2);

    // Inlines:
    //   heading: 3 ("Title with ", Bold, " word") + 1 (bold child) = 4
    //   paragraph: 2 (ExternalLink, Transclusion) + 2 (link desc) = 4
    //   list items: 2 (one each)
    //   table cells: 2 (one each)
    //   total: 12
    assert_eq!(counter.inlines, 12);
    // Text leaves: heading 3, link description 2, list items 2, table cells 2 = 9
    assert_eq!(counter.text, 9, "Text leaves");
    assert_eq!(counter.bold, 1);
    assert_eq!(counter.external_links, 1);
    assert_eq!(counter.transclusions, 1);
}

#[test]
fn document_default_is_empty() {
    let doc = DocumentNode::default();
    assert!(doc.children.is_empty());
    assert_eq!(doc.metadata.title, None);
    assert!(!doc.metadata.nohtml);

    let mut counter = Counter::default();
    counter.visit_document(&doc);
    assert_eq!(counter.blocks, 0);
    assert_eq!(counter.inlines, 0);
}