select_keywords.js

function select_keywords(r, emit) {
  try{
    var package=JSON.parse(r.content);
    (package.keywords || []).forEach(function(keyword){
      emit({keyword : keyword});
    });    
  }
  catch(ex){
  }
}

bigquery.defineFunction(
  'select_keywords', // Name of the function exported to SQL
  ['content'], // Names of input columns
  [{'name': 'keyword', 'type': 'string'}], // Output schema
  select_keywords // Reference to JavaScript UDF
);

SELECT
  keyword,
  COUNT(keyword) AS count
FROM (
  SELECT
    keyword
  FROM (select_keywords(
      SELECT
        content
      FROM
        [githubdataqueries:NpmStat.package_json_content] )) )
GROUP BY
  keyword
ORDER BY
  count DESC