Add codemode for importing sinon

[tarjei]

(I originally suggested this codemod here: skovhus/jest-codemods#53)
I do not have time to write a PR but you might want to add something like this:

/**
 * A quick code mod to move from using a sinon global to using sinon 2.x with an import statement.
 */

// findImports, hasRequireOrImport stolen from
// https://github.com/skovhus/jest-codemods/blob/master/src/utils/imports.js

function findImports (j, ast, pkg) {
  return ast.find(j.ImportDeclaration, {
    source: {
      value: pkg
    }
  })
}
/**
 * Detects CommonJS and import statements for the given package.
 * @return true if import were found, else false
 */
function hasRequireOrImport (j, ast, pkg) {
  // const requires = findRequires(j, ast, pkg).size()
  const imports = findImports(j, ast, pkg).size()
  return imports > 0
}

function hasIdentifier (j, ast, name) {
  return ast.find(j.Identifier, {
    name
  }).size() > 0
}

module.exports = function (fileInfo, api) {
  const j = api.jscodeshift
  const ast = j(fileInfo.source)

  if (!hasRequireOrImport(j, ast, 'sinon') && hasIdentifier(j, ast, 'sinon')) {
    let imp = ast.find(j.ImportDeclaration, {})
    // console.log(imp)

    let node = imp.at(imp.size() - 1)

    const {statement} = j.template
    // const newNode = j.importDeclaration('sinon', 'sinon');
    node.insertAfter(statement`import sinon from 'sinon'`)

    return node.toSource()
  }
}

[hurrymaplelad]

Thanks for sharing! PR welcome from anyone who wants to pick this up.