text-document 1.8.0

//! `to_plain_text()` must return the document's prose in **reading order**.
//!
//! It did not. `export_plain_text_uc` sorted each frame's blocks against only *their own
//! frame's* siblings, then concatenated the frames in **frame-creation order** — silently
//! assuming creation order equals document order. A blockquote becomes a *child frame*, and
//! it is created after the root frame, so every blockquote's prose was hoisted to the **end**
//! of the export:
//!
//! ```text
//! djot            "> a0\n\na"
//! to_plain_text   "a\na0"     ← the paragraph came FIRST
//! to_djot         "> a0\n\na" ← the djot exporter had it right
//! find_all sees   "a0\na"     ← so did search
//! ```
//!
//! `to_plain_text` was the only one of the three walks that was wrong. `document_position` is
//! a single global counter across the whole parse (root and every nesting depth alike), so
//! pooling every frame's blocks and sorting **once, globally** reconstructs true reading
//! order — which is exactly what `find_all` already did.
//!
//! Reachable today through this crate's own CLI (`cat` / `convert` / `replace`), which wrote
//! `to_plain_text()` straight to stdout: converting any document with a blockquote silently
//! scrambled the paragraphs.

use text_document::{DjotImportOptions, TABLE_ANCHOR, TextDocument, djot_to_plain_text};

fn plain(djot: &str) -> String {
    let doc = TextDocument::new();
    doc.set_djot(djot).unwrap().wait().unwrap();
    doc.to_plain_text().unwrap()
}

/// The reported case, minimal.
#[test]
fn a_blockquote_is_not_hoisted_to_the_end() {
    assert_eq!(
        plain("> a0\n\na"),
        "a0\na",
        "the quotation is written first, so it must be read first"
    );
}

/// The interleaving must survive, not just the first pair.
#[test]
fn quotes_and_paragraphs_keep_their_interleaving() {
    assert_eq!(plain("p1\n\n> q1\n\np2\n\n> q2"), "p1\nq1\np2\nq2");
    assert_eq!(plain("a\n\n> a0\n\nb"), "a\na0\nb");
    assert_eq!(plain("> a0\n\na\n\n> a1"), "a0\na\na1");
    assert_eq!(plain("> a0\n\n> a1\n\na"), "a0\na1\na");
}

/// Hoisting was not specific to paragraphs — any top-level block after a quote was pulled in
/// front of it.
#[test]
fn a_quote_is_not_hoisted_past_a_heading_a_list_or_a_fence() {
    assert_eq!(plain("> a0\n\n# h"), "a0\nh");
    assert_eq!(plain("> a0\n\n- item"), "a0\nitem");
    assert_eq!(plain("> a0\n\n```\ncode\n```"), "a0\ncode");
}

/// Nested blockquotes, and a quote holding several blocks, must also stay in place.
#[test]
fn nested_and_multi_block_quotes_stay_in_place() {
    assert_eq!(
        plain("> outer\n>\n> > inner\n\nafter"),
        "outer\ninner\nafter"
    );
    assert_eq!(
        plain("> p1\n>\n> p2\n\nafter"),
        "p1\np2\nafter",
        "a quote's own blocks stay in order AND stay before what follows the quote"
    );
}

/// Table cells sit where the table sits.
#[test]
fn a_table_stays_where_it_was_written() {
    assert_eq!(
        plain("intro\n\n| a | b |\n| - | - |\n| c | d |\n\nafter"),
        "intro\na\nb\nc\nd\nafter"
    );
}

/// **The tie that makes a future divergence impossible to miss.**
///
/// `to_plain_text()` is the *human-readable* view: prose, with no object anchors — which is
/// why the crate's own fast path bails the moment a table exists. `djot_to_plain_text()` is
/// the *addressable* view: character-for-character the text the document searches, table
/// anchors and all.
///
/// They are allowed to differ in exactly one way — the anchors — and in no other. Pin that,
/// so the two can never drift on ORDER again, which is the drift that caused this bug.
#[test]
fn the_human_view_is_the_addressable_view_minus_its_anchors() {
    for src in [
        "> a0\n\na",
        "p1\n\n> q1\n\np2\n\n> q2",
        "intro\n\n| a | b |\n| - | - |\n| c | d |\n\nafter",
        "> quoted\n\n# head\n\n- item\n\n| x |\n| - |\n| y |",
        "a\n\nb\n\nc",
    ] {
        let addressable = djot_to_plain_text(src, &DjotImportOptions::default());
        let without_anchors: Vec<&str> = addressable
            .split('\n')
            .filter(|line| *line != TABLE_ANCHOR)
            .collect();

        assert_eq!(
            plain(src),
            without_anchors.join("\n"),
            "to_plain_text() and the document's addressable text disagree about more than \
             anchors, for {src:?} — the only sanctioned difference is the object anchors"
        );
    }
}