eslint-plugin-jest/lib/rules/no-large-snapshots.js

Eslint rules for Jest

'use strict';

const _require = require('./util'),
      getDocsUrl = _require.getDocsUrl;

const reportOnViolation = (context, node) => {
  const lineLimit = context.options[0] && Number.isFinite(context.options[0].maxSize) ? context.options[0].maxSize : 50;
  const startLine = node.loc.start.line;
  const endLine = node.loc.end.line;
  const lineCount = endLine - startLine;

  if (lineCount > lineLimit) {
    context.report({
      messageId: lineLimit === 0 ? 'noSnapshot' : 'tooLongSnapshots',
      data: {
        lineLimit,
        lineCount
      },
      node
    });
  }
};

module.exports = {
  meta: {
    docs: {
      url: getDocsUrl(__filename)
    },
    messages: {
      noSnapshot: '`{{ lineCount }}`s should begin with lowercase',
      tooLongSnapshots: 'Expected Jest snapshot to be smaller than {{ lineLimit }} lines but was {{ lineCount }} lines long'
    }
  },

  create(context) {
    if (context.getFilename().endsWith('.snap')) {
      return {
        ExpressionStatement(node) {
          reportOnViolation(context, node);
        }

      };
    } else if (context.getFilename().endsWith('.js')) {
      return {
        CallExpression(node) {
          const propertyName = node.callee.property && node.callee.property.name;

          if (propertyName === 'toMatchInlineSnapshot' || propertyName === 'toThrowErrorMatchingInlineSnapshot') {
            reportOnViolation(context, node);
          }
        }

      };
    }

    return {};
  }

};