function addBodyPrefixSuffixToContext()

in src/plugins/console/public/lib/autocomplete/autocomplete.ts [672:768]
80 lines of code
29 McCabe index (conditional complexity)

  function addBodyPrefixSuffixToContext(context: any) {
    // Figure out what happens next to the token to see whether it needs trailing commas etc.

    // Templates will be used if not destroying existing structure.
    // -> token : {} or token ]/} or token , but not token : SOMETHING ELSE

    context.prefixToAdd = '';
    context.suffixToAdd = '';

    let tokenIter = createTokenIterator({
      editor,
      position: editor.getCurrentPosition()!,
    });
    let nonEmptyToken = parser.nextNonEmptyToken(tokenIter);
    switch (nonEmptyToken ? nonEmptyToken.type : 'NOTOKEN') {
      case 'NOTOKEN':
      case 'paren.lparen':
      case 'paren.rparen':
      case 'punctuation.comma':
        context.addTemplate = true;
        break;
      case 'punctuation.colon':
        // test if there is an empty object - if so we replace it
        context.addTemplate = false;

        nonEmptyToken = parser.nextNonEmptyToken(tokenIter);
        if (!(nonEmptyToken && nonEmptyToken.value === '{')) {
          break;
        }
        nonEmptyToken = parser.nextNonEmptyToken(tokenIter);
        if (!(nonEmptyToken && nonEmptyToken.value === '}')) {
          break;
        }
        context.addTemplate = true;
        // extend range to replace to include all up to token
        context.rangeToReplace.end.lineNumber = tokenIter.getCurrentTokenLineNumber();
        context.rangeToReplace.end.column =
          tokenIter.getCurrentTokenColumn() + nonEmptyToken.value.length;

        // move one more time to check if we need a trailing comma
        nonEmptyToken = parser.nextNonEmptyToken(tokenIter);
        switch (nonEmptyToken ? nonEmptyToken.type : 'NOTOKEN') {
          case 'NOTOKEN':
          case 'paren.rparen':
          case 'punctuation.comma':
          case 'punctuation.colon':
            break;
          default:
            context.suffixToAdd = ', ';
        }

        break;
      default:
        context.addTemplate = true;
        context.suffixToAdd = ', ';
        break; // for now play safe and do nothing. May be made smarter.
    }

    // go back to see whether we have one of ( : { & [ do not require a comma. All the rest do.
    tokenIter = createTokenIterator({ editor, position: editor.getCurrentPosition() });
    nonEmptyToken = tokenIter.getCurrentToken();
    let insertingRelativeToToken; // -1 is before token, 0 middle, +1 after token
    if (context.replacingToken) {
      insertingRelativeToToken = 0;
    } else {
      const pos = editor.getCurrentPosition();
      if (pos.column === context.updatedForToken.position.column) {
        insertingRelativeToToken = -1;
      } else if (
        pos.column <
        context.updatedForToken.position.column + context.updatedForToken.value.length
      ) {
        insertingRelativeToToken = 0;
      } else {
        insertingRelativeToToken = 1;
      }
    }
    // we should actually look at what's happening before this token
    if (parser.isEmptyToken(nonEmptyToken) || insertingRelativeToToken <= 0) {
      nonEmptyToken = parser.prevNonEmptyToken(tokenIter);
    }

    switch (nonEmptyToken ? nonEmptyToken.type : 'NOTOKEN') {
      case 'NOTOKEN':
      case 'paren.lparen':
      case 'punctuation.comma':
      case 'punctuation.colon':
      case 'method':
        break;
      default:
        if (nonEmptyToken && nonEmptyToken.type.indexOf('url') < 0) {
          context.prefixToAdd = ', ';
        }
    }

    return context;
  }