All files / json-ot/types/ot-string util.ts

100% Statements 64/64
100% Branches 34/34
100% Functions 6/6
100% Lines 49/49

Press n or j to go to the next uncovered block, b, p or k for the previous block.

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94    3x 28281x 28279x 5508x 5508x   22771x 22771x 22771x   11191x 4697x 3697x 2220x 6494x 11191x     6380x 4525x 6380x     5200x 3645x 5200x         3x 14636x   7538x   3612x   3486x       3x 6084x   3216x   1509x   1359x       3x 3371x 3365x 3365x 3365x     3x 2150x 2150x 8518x 2150x 2150x                     3x 6770x   3106x     1908x 1908x     1756x 1756x 1756x        
import type {StringOp, StringOpComponent} from './types';
 
export const append = (op: StringOp, component: StringOpComponent): void => {
  if (!component) return;
  if (!op.length) {
    op.push(component);
    return;
  }
  const lastIndex = op.length - 1;
  const last = op[lastIndex];
  switch (typeof component) {
    case 'number': {
      if (typeof last === 'number') {
        if (component > 0 && last > 0) op[lastIndex] = last + component;
        else if (component < 0 && last < 0) op[lastIndex] = last + component;
        else op.push(component);
      } else op.push(component);
      break;
    }
    case 'string': {
      if (typeof last === 'string') op[lastIndex] = last + component;
      else op.push(component);
      break;
    }
    case 'object': {
      if (last instanceof Array) last[0] = last + component[0];
      else op.push(component);
      break;
    }
  }
};
 
export const componentLength = (component: StringOpComponent): number => {
  switch (typeof component) {
    case 'number':
      return Math.abs(component);
    case 'string':
      return component.length;
    default:
      return component[0].length;
  }
};
 
export const isDeleteComponent = (component: StringOpComponent): boolean => {
  switch (typeof component) {
    case 'number':
      return component < 0;
    case 'object':
      return true;
    default:
      return false;
  }
};
 
export const trim = (op: StringOp): void => {
  if (!op.length) return;
  const last = op[op.length - 1];
  const isLastRetain = typeof last === 'number' && last > 0;
  if (isLastRetain) op.pop();
};
 
export const normalize = (op: StringOp): StringOp => {
  const op2: StringOp = [];
  const length = op.length;
  for (let i = 0; i < length; i++) append(op2, op[i]);
  trim(op2);
  return op2;
};
 
/**
 * Extracts a full or a part of a component from an operation.
 *
 * @param component Component from which to extract a chunk.
 * @param offset Position within the component to start from.
 * @param maxLength Maximum length of the component to extract.
 * @returns Full or partial component at index `index` of operation `op`.
 */
export const chunk = (component: StringOpComponent, offset: number, maxLength: number): StringOpComponent => {
  switch (typeof component) {
    case 'number': {
      return component > 0 ? Math.min(component - offset, maxLength) : -Math.min(-component - offset, maxLength);
    }
    case 'string': {
      const end = Math.min(offset + maxLength, component.length);
      return component.substring(offset, end);
    }
    case 'object': {
      const str = component[0];
      const end = Math.min(offset + maxLength, str.length);
      return [str.substring(offset, end)];
    }
  }
};