return 0 !== n.indexOf("function") ? "production" : -1 !== n.indexOf("storedMeasure") ? "development" : -1 !== n.indexOf("should be a pure function") ? -1 !== n.indexOf("NODE_ENV") || -1 !== n.indexOf("development") || -1 !== n.indexOf("true") ? "development" : -1 !== n.indexOf("nextElement") || -1 !== n.indexOf("nextComponent") ? "unminified" : "development" : -1 !== n.indexOf("nextElement") || -1 !== n.indexOf("nextComponent") ? "unminified" : "outdated"; /** Explanation Breaking it Down: First Condition: 0 !== n.indexOf("function") ? "production" If the string n contains "function" anywhere except at the start (indexOf("function") returns something other than 0), return "production". Second Condition: =============== If "storedMeasure" is found in n, return "development". Third Condition: =============== If "should be a pure function" is found, check further conditions: Fourth Condition (nested within the third): =============== If "NODE_ENV", "development", or "true" are found, return "development". Fifth Condition (if the above is false): =============== If "nextElement" or "nextComponent" is found, return "unminified", otherwise return "development". Final Condition (if "should be a pure function" was NOT found): =============== If "nextElement" or "nextComponent" is found, return "unminified", otherwise return "outdated". */