src/rules/no-unassigned-import.js

import path from 'path';
import minimatch from 'minimatch';
import { getPhysicalFilename } from 'eslint-module-utils/contextCompat';

import isStaticRequire from '../core/staticRequire';
import docsUrl from '../docsUrl';

function report(context, node) {
  context.report({
    node,
    message: 'Imported module should be assigned',
  });
}

function testIsAllow(globs, filename, source) {
  if (!Array.isArray(globs)) {
    return false; // default doesn't allow any patterns
  }

  let filePath;

  if (source[0] !== '.' && source[0] !== '/') { // a node module
    filePath = source;
  } else {
    filePath = path.resolve(path.dirname(filename), source); // get source absolute path
  }

  return globs.find((glob) => minimatch(filePath, glob)
    || minimatch(filePath, path.join(process.cwd(), glob)),
  ) !== undefined;
}

function create(context) {
  const options = context.options[0] || {};
  const filename = getPhysicalFilename(context);
  const isAllow = (source) => testIsAllow(options.allow, filename, source);

  return {
    ImportDeclaration(node) {
      if (node.specifiers.length === 0 && !isAllow(node.source.value)) {
        report(context, node);
      }
    },
    ExpressionStatement(node) {
      if (
        node.expression.type === 'CallExpression'
        && isStaticRequire(node.expression)
        && !isAllow(node.expression.arguments[0].value)
      ) {
        report(context, node.expression);
      }
    },
  };
}

module.exports = {
  create,
  meta: {
    type: 'suggestion',
    docs: {
      category: 'Style guide',
      description: 'Forbid unassigned imports',
      url: docsUrl('no-unassigned-import'),
    },
    schema: [
      {
        type: 'object',
        properties: {
          devDependencies: { type: ['boolean', 'array'] },
          optionalDependencies: { type: ['boolean', 'array'] },
          peerDependencies: { type: ['boolean', 'array'] },
          allow: {
            type: 'array',
            items: {
              type: 'string',
            },
          },
        },
        additionalProperties: false,
      },
    ],
  },
};