Function getVariableMappings

lib/vars.js:56–116

(themes)

// Get unique variables, static variables, and a mapping of original variable names.
function getVariableMappings(themes) {
  let themeVars = {};
  for (let theme of themes) {
    let values = getVars(
      `${__dirname}/../packages/@adobe/spectrum-css-temp/vars/spectrum-${theme}.css`
    );
    let mappings = getUniqueVars(values);
    themeVars[theme] = {values, mappings};
  }

  let {values, mappings} = themeVars[themes[0]];
  let mapping = {};
  let staticVars = {};
  let vars = {};
  for (let v in mappings) {
    // If the variable does not change values across themes, save it in the static variables list
    let isStatic = themes.every(t => themeVars[t].values[v] === values[v]);
    if (isStatic) {
      staticVars[v] = values[v];
      continue;
    }

    // Find a variable that exists in the mappings across all themes
    let mapped = mappings[v].find(mapped => {
      return themes.every(t => {
        return themeVars[t].mappings[v].includes(mapped);
      });
    });

    if (!mapped) {
      throw new Error('Could not find mapping');
    }

    // If the variable maps to itself, add it to the mapping of unique variables
    if (mapped === v) {
      for (let t of themes) {
        if (!vars[t]) {
          vars[t] = {};
        }

        vars[t][v] = themeVars[t].values[v];
      }
    } else {
      // Otherwise, map the variable to one of the unique variables.
      mapping[v] = mapped;
    }
  }

  for (let mapped in mapping) {
    for (let t of themes) {
      if (
        themeVars[t].values[mapped] !== themeVars[t].values[mapping[mapped]] ||
        !vars[t][mapping[mapped]]
      ) {
        throw new Error('Invalid mapping ' + mapped + ' ' + mapping[mapped]);
      }
    }
  }