yaml-edit/index.js

Library for editing yaml files

'use strict';

module.exports = (input) => {
  let yaml = input;

  function search(place) {
    let lines = yaml.split(/\n/);
    let indentlevel = 0;
    let levelname = '';
    let context = [];
    let found = false;
    let before = [];
    let after = [];
    lines.map((line, idx) => {
      let parts = line.match(/^( *)([^ :]+):/);
      if (parts) {
        indentlevel = parts[1].length / 2 || 0;
        levelname = parts[2];
        context[indentlevel] = levelname;
        let currContext = context.slice(0, indentlevel+1).join('.');
        if (found) {
          after.push(line);
        } else {
          before.push(line);
        }
        if (currContext == place) {
          found = true;
        }
      } else {
        if (found) {
          after.push(line);
        } else {
          before.push(line);
        }
      }
      
    });
    return [ 
      before.join('\n'), 
      after.join('\n')
    ];
  }

  function generateSnippet(doc, indentLevel, isArray) {
    let keys = Object.keys(doc);
    let snippet = '';
    let lines = [];
    let indent = ' '.repeat(indentLevel * 2);
    if (isArray) {
      indent = indent.replace(/  $/, '- ');
    }

    keys.map((k, idx) => {
      let val = doc[k];
      
      if (typeof(val) != 'object') {
        lines.push(indent + k + ': ' + val);
      } else {
        lines.push(indent + k + ':');
        if (Array.isArray(val)) {
          val.map((arrItem, idx2) => {
            let arrLines=generateSnippet(arrItem, indentLevel+2, true);
            lines = lines.concat(arrLines);
          });
        } else {
          lines = lines.concat(generateSnippet(val, indentLevel + 1));
        }       
      }
    });

    return lines.join('\n');
  }

  return {
    dump: () => {
      return yaml;
    },
    init: (input) => {
      yaml = input;
      return module.exports;
    },
    hasKey: (place) => {
      const parts = search(place);
      if (parts[1].length == 0) {
        return false;
      } else {
        return true;
      }
    },
    insertChild: (place, doc) => {
      let parts = search(place);
      let begin = parts[0];
      let end = parts[1];
      if (! end) {
        return new Error(`Could not find place`);
      }
      let indentLevel = place.split('.').length;
      let insertText = generateSnippet(doc, indentLevel);

      yaml = [begin, insertText, end].join('\n');
      return null;
    }
  }
}