ServiceNow Personal Best Practices Checklist

[Amit Gujarathi]

Best Practices Checklist

1. Readable Code

• Code should have proper alignment and readable.
• Include comments appropriately, so it helps the reader to understand the purpose my piece code serves.
• Use Descriptive Variable and Function Names
  • Function name should be verb.
  • variable name should be noun

2. Naming Convention

• Capitalize constructors: MyConstructor()
• Functions lower camel case: lowerCamelCase()
• variables: myLocalVariable
• constants: MY_CONSTANT
• private: _myPrivateMethod()

3. Variables Properties

• Check if the script returns a 'null' OR 'undefined' and handle it appropriately.
• Use 'var' keyword for all your variables to prevent from accidently creating global variables.
• Embed code and variable declarations into functions

4. Handel Exception

• Use 'try' and 'catch' to handle exceptions
• Use a MAX_LOOP variable to prevent endless loops.

5. Avoid calling repeated function

• Avoid repeated function calls by calling the functions once and storing the returned values/object in a variable and use these variables as required. For example

              var ourUser = gs.getUser();

              gs.­print(­ourUser.­getFirstName());

              gs.­print (­ourUser. getLastName());

• Use g_scratchpad - use this when required as this can be used to store parent data so instead of multiple server round trips use this to cache the data.
• Construct reusable function.

6. String Comparision

• The strings to be compared should be in the same case. Use toUpperCase() and toLowerCase() functions as required before string comparison.

7. Remove unwanted code

• Remove all gs.log, gs.addinfoMessage(), alert(), etc. and unwanted code statements before marking the update set as 'complete'.

8. Servicenow best practices

• Don't use current.update in a business rule
• Don’t' use global business rules - Use script includes
• Don't use RowCount - Count records with GlideAggregate
• Don't hard coded sys_id's and other strings like 'manager_name' or 'group_name'.
• Do not use glideRecord or g_form.getReference() in client scripts. Instead, use a GlideAjax call to that function asynchronously.
• Use "Switch" statement to handle multiple conditions instead of if-else.

9. GlideRecord

• Rather than creating a series of addQuery() and addOrCondition() calls to obtain a result, use addEncodedQuery() to make the query easier to create and maintain.
• Avoid Complex Queries on Large Data Sets: Limit the number of times you search large tables. As your instance grows, these searches can affect performance.

10. Update Sets

• Follow Naming Standards : A consistent naming system for update sets makes it easier to coordinate changes from multiple developers or when applying changes from one instance to another one.
• Provide descriptions for update sets.
• Inspect your update set: Check that it contains only the desired changes. Remove any unwanted changes that were captured while development.
• Do not make an update set in 'Complete' state to 'In Progress' again and try to capture changes into that. After a completed update set is transferred to another instance, any future changes to the source update set are ignored.

11. JS Docs comments

• Add JSDOC comments

    12.  JSON

• do not use "new JSON().encode" & "answer.evalJSON "instead use JSON.stringify(answer) & JSON.parse(answer) respectively. Always check first if the JSON object has the key which you are referring to.

   13. Others

• Each 'if' statement should have braces enclosed
• Before calling function, check whether function parameter for null value