From afd7cf51cf651180707886467f945f2022500782 Mon Sep 17 00:00:00 2001
From: Sidharth Vinod <sidharthv96@gmail.com>
Date: Thu, 14 Sep 2023 22:46:43 +0530
Subject: [PATCH] fix: Types and nomenclature

---
 packages/mermaid/src/diagrams/packet/db.ts     | 18 ++++++++++--------
 .../mermaid/src/diagrams/packet/renderer.ts    | 10 +++++-----
 packages/mermaid/src/diagrams/packet/types.ts  |  4 ++--
 3 files changed, 17 insertions(+), 15 deletions(-)

diff --git a/packages/mermaid/src/diagrams/packet/db.ts b/packages/mermaid/src/diagrams/packet/db.ts
index a36fdcaf1..0773a2c0e 100644
--- a/packages/mermaid/src/diagrams/packet/db.ts
+++ b/packages/mermaid/src/diagrams/packet/db.ts
@@ -1,11 +1,11 @@
-import type { Block, PacketDB, Word } from './types.js';
+import type { Block, PacketDB, Row } from './types.js';
 import { log } from '../../logger.js';
 import type { PacketDiagramConfig } from '../../config.type.js';
 import DEFAULT_CONFIG from '../../defaultConfig.js';
 import { getConfig as commonGetConfig } from '../../config.js';
 
 interface PacketData {
-  packet: Word[];
+  packet: Row[];
 }
 
 const defaultPacketData: PacketData = {
@@ -22,21 +22,23 @@ export const getConfig = (): Required<PacketDiagramConfig> => {
   });
 };
 
-export const getPacket = (): Word[] => data.packet;
+export const getPacket = (): Row[] => data.packet;
 
 export const getNextFittingBlock = (
   block: Block,
   row: number,
   bitsPerRow: number
-): [Block, Block | undefined] => {
-  block.end = block.end ?? block.start;
+): [Required<Block>, Block | undefined] => {
+  if (block.end === undefined) {
+    block.end = block.start;
+  }
 
   if (block.start > block.end) {
     throw new Error(`Block start ${block.start} is greater than block end ${block.end}.`);
   }
 
   if (block.end + 1 <= row * bitsPerRow) {
-    return [block, undefined];
+    return [block as Required<Block>, undefined];
   }
 
   return [
@@ -55,12 +57,12 @@ export const getNextFittingBlock = (
 
 export const populate = ({ blocks }: { blocks: Block[] }) => {
   let lastByte = -1;
-  let word: Block[] = [];
+  let word: Row = [];
   data.packet = [];
   let row = 1;
   const { bitsPerRow } = getConfig();
   for (let { start, end, label } of blocks) {
-    if (end < start) {
+    if (end && end < start) {
       throw new Error(`Packet block ${start} - ${end} is invalid. End must be greater than start.`);
     }
     if (start != lastByte + 1) {
diff --git a/packages/mermaid/src/diagrams/packet/renderer.ts b/packages/mermaid/src/diagrams/packet/renderer.ts
index 640c2e870..d6d2a3d2e 100644
--- a/packages/mermaid/src/diagrams/packet/renderer.ts
+++ b/packages/mermaid/src/diagrams/packet/renderer.ts
@@ -1,7 +1,7 @@
 import { configureSvgSize } from '../../setupGraphViewbox.js';
 import type { DrawDefinition, Group, SVG } from '../../diagram-api/types.js';
 import { selectSvgElement } from '../../rendering-util/selectSvgElement.js';
-import type { PacketDB, Word } from './types.js';
+import type { PacketDB, Row } from './types.js';
 import type { PacketDiagramConfig } from '../../config.type.js';
 import type { Diagram } from '../../Diagram.js';
 
@@ -25,13 +25,13 @@ const draw: DrawDefinition = (_text, id, _version, diagram: Diagram) => {
 
 const drawWord = (
   svg: SVG,
-  word: Word,
-  row: number,
+  row: Row,
+  rowNumber: number,
   { rowHeight, paddingX, paddingY, bitWidth, bitsPerRow }: Required<PacketDiagramConfig>
 ) => {
   const group: Group = svg.append('g');
-  const wordY = row * (rowHeight + paddingY) + paddingY;
-  for (const block of word) {
+  const wordY = rowNumber * (rowHeight + paddingY) + paddingY;
+  for (const block of row) {
     const blockX = (block.start % bitsPerRow) * bitWidth + 1;
     const width = (block.end - block.start + 1) * bitWidth - paddingX;
     // Block rectangle
diff --git a/packages/mermaid/src/diagrams/packet/types.ts b/packages/mermaid/src/diagrams/packet/types.ts
index 9100558eb..5492d4004 100644
--- a/packages/mermaid/src/diagrams/packet/types.ts
+++ b/packages/mermaid/src/diagrams/packet/types.ts
@@ -3,8 +3,8 @@ import type { DiagramDB } from '../../diagram-api/types.js';
 
 export type ArrayElement<A> = A extends readonly (infer T)[] ? T : never;
 export type Block = Pick<ArrayElement<Packet['blocks']>, 'start' | 'end' | 'label'>;
-export type Word = Block[];
+export type Row = Required<Block>[];
 
 export interface PacketDB extends DiagramDB {
-  getPacket: () => Word[];
+  getPacket: () => Row[];
 }