MedplumCodeBlock.tsx•4.37 kB
import CodeBlock, { Props } from '@theme/CodeBlock';
import { JSX } from 'react';
const BLOCK_START_PATTERN = /^\s*\/\/\s*start-block\s+([A-Za-z_-]*)/;
const BLOCK_END_PATTERN = /^\s*\/\/\s*end-block\s+([A-Za-z_-]*)/;
interface MedplumCodeBlockProps extends Props {
readonly selectLines?: number[][];
readonly selectBlocks?: string;
}
export default function MedplumCodeBlock({
children,
selectLines,
selectBlocks,
...props
}: MedplumCodeBlockProps): JSX.Element {
let code = children as string;
if (selectLines && selectBlocks) {
throw new Error("Only one of 'selectLines' or 'selectBlocks' can be specified");
}
let codeLines: string[] = code.split('\n');
// Get the line ranges for all the blocks that have been selected.
const linesToRemove = new Set<number>();
const blockRanges = extractBlocks(codeLines);
// Save the line numbers of the magic comments, so that they can be removed later
Object.values(blockRanges)
.flat()
.forEach((lineNumber) => linesToRemove.add(lineNumber));
if (selectBlocks) {
const selectBlockNames = selectBlocks.split(',').map((s) => s.trim());
selectLines = selectBlockNames.map((block) => {
if (!(block in blockRanges)) {
throw new Error(`No such code block: '${block}'`);
}
return blockRanges[block];
});
}
// Set all the magic comment lines to 'null' to be filtered out later
// We do this to preserve line numbers before slicing codeLines
linesToRemove.forEach((lineNumber) => (codeLines[lineNumber - 1] = null));
// For each line range to be selected, grab the slice from the original code
if (selectLines) {
codeLines = selectLines.flatMap((range) =>
range.length === 1 ? codeLines[range[0] - 1] : codeLines.slice(range[0] - 1, range[1])
);
}
// Filter out lines that were set to null
codeLines = codeLines.filter((line) => line !== null);
// Find the minimum indentation
const minIndent = findMinimumIndentation(codeLines);
// Remove the minimum indentation from all lines
codeLines = codeLines.map((line) => removeIndentation(line, minIndent));
code = codeLines.join('\n');
return <CodeBlock {...props}>{code}</CodeBlock>;
}
/**
* Returns an map from the block name to the start and stop lines for that block
* @param codeLines - Array of code lines.
* @returns The code blocks.
*/
function extractBlocks(codeLines: string[]): Record<string, [number, number]> {
const results: Record<string, [number, number | undefined]> = {};
for (let i = 0; i < codeLines.length; i++) {
const line = codeLines[i];
// If we are beginning a new block, save the starting line number
const startMatch = BLOCK_START_PATTERN.exec(line);
if (startMatch) {
const blockName = startMatch[1];
if (blockName in results) {
throw new Error(`Block ${blockName} declared more than once`);
}
results[blockName] = [i + 1, undefined];
}
const endMatch = BLOCK_END_PATTERN.exec(line);
if (endMatch) {
const blockName = endMatch[1];
if (!(blockName in results)) {
throw new Error(`Block ${blockName} is closed on line ${i + 1} before it is started`);
}
if (results[blockName][1]) {
throw new Error(
`Block ${blockName} closed more than once. First on line ${results[blockName][1]} and then on line ${i + 1})`
);
}
results[blockName][1] = i + 1;
}
}
const unterminatedBlocks = Object.entries(results).filter(([_, range]) => !range[1]);
if (unterminatedBlocks.length > 0) {
throw new Error(`Unterminated blocks: ${unterminatedBlocks.map((e) => e[0]).join(', ')}`);
}
return results;
}
/**
* Finds the minimum indentation across all non-empty lines
* @param lines - Array of code lines.
* @returns The minimum indentation.
*/
function findMinimumIndentation(lines: string[]): number {
const indentations = lines.filter((line) => line.trim().length > 0).map((line) => line.match(/^\s*/)[0].length);
return Math.min(...indentations);
}
/**
* Removes a specified amount of indentation from a line
* @param line - The line to remove indentation from.
* @param indent - The amount of indentation to remove.
* @returns The line with reduced indentation.
*/
function removeIndentation(line: string, indent: number): string {
return line.slice(indent);
}
