1- import React from "react" ;
1+ import React , { useEffect , useState } from "react" ;
22import CodeBlock from "@theme/CodeBlock" ;
33
44interface SnippetProps extends React . ComponentProps < typeof CodeBlock > {
@@ -8,27 +8,73 @@ interface SnippetProps extends React.ComponentProps<typeof CodeBlock> {
88 lines ?: string ;
99 omitted_placeholder ?: string ;
1010 strip_leading_spaces ?: boolean ;
11+ /**
12+ * Optional short hash of the content (first N characters of SHA-256),
13+ * required only when `lines` is specified.
14+ */
15+ hash ?: string ;
1116}
1217
1318/**
1419 * A component for rendering a snippet of code, optionally filtering lines,
15- * showing ellipses for omissions, and stripping all leading spaces.
20+ * showing ellipses for omissions, stripping leading spaces, and validating hash .
1621 */
1722const Snippet : React . FC < SnippetProps > = ( {
1823 children,
1924 lines,
2025 omitted_placeholder = "..." ,
2126 strip_leading_spaces = false ,
27+ hash,
2228 ...props
2329} ) => {
30+ const [ error , setError ] = useState < string | null > ( null ) ;
31+
2432 if ( typeof children !== "string" ) {
25- console . error (
33+ throw new Error (
2634 "Snippet expects children to be a string containing the file content."
2735 ) ;
28- return null ;
2936 }
3037
31- // Parse the `linesToInclude` metadata string into an array of line numbers.
38+ /**
39+ * Utility function to compute the SHA-256 hash of a string.
40+ * @param content The input string
41+ * @returns Promise resolving to a hex-encoded hash
42+ */
43+ const computeHash = async ( content : string ) : Promise < string > => {
44+ const encoder = new TextEncoder ( ) ;
45+ const data = encoder . encode ( content ) ;
46+ const hashBuffer = await crypto . subtle . digest ( "SHA-256" , data ) ;
47+ return Array . from ( new Uint8Array ( hashBuffer ) )
48+ . map ( ( byte ) => byte . toString ( 16 ) . padStart ( 2 , "0" ) )
49+ . join ( "" ) ;
50+ } ;
51+
52+ useEffect ( ( ) => {
53+ if ( lines ) {
54+ computeHash ( children ) . then ( ( computedHash ) => {
55+ const shortHash = computedHash . slice ( 0 , 7 ) ; // Use 7 characters for the short hash
56+
57+ if ( ! hash ) {
58+ setError (
59+ `The \`hash\` prop is required when \`lines\` is specified.\n` +
60+ `Provide the following hash as the \`hash\` prop: ${ shortHash }
61+ ) ;
62+ } else if ( shortHash !== hash ) {
63+ setError (
64+ `Snippet hash mismatch.\n` +
65+ `Specified: ${ hash } ${ shortHash } ${ computedHash } +
66+ `Check if the line numbers are still relevant and update the hash.`
67+ ) ;
68+ }
69+ } ) ;
70+ }
71+ } , [ children , lines , hash ] ) ;
72+
73+ if ( error ) {
74+ throw new Error ( error ) ;
75+ }
76+
77+ // Parse the `lines` metadata string into an array of line numbers.
3278 const parseLineRanges = ( metaString ?: string ) : number [ ] => {
3379 if ( ! metaString ) return [ ] ;
3480 return metaString . split ( "," ) . flatMap ( ( range ) => {
@@ -46,16 +92,27 @@ const Snippet: React.FC<SnippetProps> = ({
4692 if ( lines . length === 0 ) return content ; // If no specific lines are specified, return full content.
4793
4894 const includedContent : string [ ] = [ ] ;
95+
96+ // Filter lines and find the minimum indentation
97+ const selectedLines = lines
98+ . map ( ( line ) => allLines [ line - 1 ] || "" )
99+ . filter ( ( line ) => line . trim ( ) . length > 0 ) ; // Ignore blank lines
100+
101+ const minIndent = selectedLines . reduce ( ( min , line ) => {
102+ const indentMatch = line . match ( / ^ ( \s * ) \S / ) ;
103+ const indentLength = indentMatch ? indentMatch [ 1 ] . length : 0 ;
104+ return Math . min ( min , indentLength ) ;
105+ } , Infinity ) ;
106+
49107 lines . forEach ( ( line , index ) => {
50108 if ( index > 0 && lines [ index - 1 ] < line - 1 ) {
51109 includedContent . push ( omitted_placeholder ) ; // Add placeholder for omitted lines
52110 }
53111
54112 const rawLine = allLines [ line - 1 ] || "" ;
55- const formattedLine = strip_leading_spaces
56- ? rawLine . trimStart ( )
57- : rawLine ;
58- includedContent . push ( formattedLine ) ;
113+ const trimmedLine =
114+ rawLine . trim ( ) . length > 0 ? rawLine . slice ( minIndent ) : rawLine ;
115+ includedContent . push ( trimmedLine ) ;
59116 } ) ;
60117
61118 // Add placeholder if lines at the end are omitted
0 commit comments