ftml 0.5.0

/*
 * render/json.rs
 *
 * ftml - Library to parse Wikidot text
 * Copyright (C) 2019-2021 Wikijump Team
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with this program. If not, see <http://www.gnu.org/licenses/>.
 */

//! A simple renderer that outputs the `SyntaxTree` as JSON.
//!
//! This implementation of `Render` will produce the same JSON
//! output as is used in the AST tests at `src/test.rs`.

use super::prelude::*;

#[derive(Debug)]
pub struct JsonRender {
    /// Whether to use the human-readable JSON formatter or the minified formatter.
    pub pretty: bool,
}

impl JsonRender {
    #[inline]
    pub fn pretty() -> Self {
        JsonRender { pretty: true }
    }

    #[inline]
    pub fn compact() -> Self {
        JsonRender { pretty: false }
    }
}

impl Render for JsonRender {
    type Output = String;

    fn render(&self, tree: &SyntaxTree) -> String {
        let writer = if self.pretty {
            serde_json::to_string_pretty
        } else {
            serde_json::to_string
        };

        writer(tree).expect("Unable to serialize JSON")
    }
}

#[test]
fn json() {
    // Expected outputs
    const PRETTY_OUTPUT: &str = r#"{
  "elements": [
    {
      "element": "text",
      "data": "apple"
    },
    {
      "element": "text",
      "data": " "
    },
    {
      "element": "container",
      "data": {
        "type": "strong",
        "elements": [
          {
            "element": "text",
            "data": "banana"
          }
        ]
      }
    }
  ],
  "styles": [
    "span.hidden-text { display: none; }"
  ]
}"#;

    const COMPACT_OUTPUT: &str = "{\"elements\":[{\"element\":\"text\",\"data\":\"apple\"},{\"element\":\"text\",\"data\":\" \"},{\"element\":\"container\",\"data\":{\"type\":\"strong\",\"elements\":[{\"element\":\"text\",\"data\":\"banana\"}]}}],\"styles\":[\"span.hidden-text { display: none; }\"]}";

    // Syntax tree construction
    let elements = vec![
        text!("apple"),
        text!(" "),
        Element::Container(Container::new(ContainerType::Strong, vec![text!("banana")])),
    ];
    let warnings = vec![];
    let styles = vec![cow!("span.hidden-text { display: none; }")];

    let result = SyntaxTree::from_element_result(elements, warnings, styles);
    let (tree, _) = result.into();

    // Perform renderings
    let output = JsonRender::pretty().render(&tree);
    assert_eq!(
        output, PRETTY_OUTPUT,
        "Pretty JSON syntax tree output doesn't match",
    );

    let output = JsonRender::compact().render(&tree);
    assert_eq!(
        output, COMPACT_OUTPUT,
        "Compact JSON syntax tree output doesn't match",
    );
}