front_end/testing/SourceMapEncoder.ts - devtools/devtools-frontend - Git at Google

 // Copyright 2021 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.

 import * as SDK from '../core/sdk/sdk.js';

 const base64Digits = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/';

 export function encodeVlq(n: number): string {
   // Set the sign bit as the least significant bit.
   n = n >= 0 ? 2 * n : 1 - 2 * n;
   // Encode into a base64 run.
   let result = '';
   while (true) {
     // Extract the lowest 5 bits and remove them from the number.
     const digit = n & 0x1f;
     n >>= 5;
     // Is there anything more left to encode?
     if (n === 0) {
       // We are done encoding, finish the run.
       result += base64Digits[digit];
       break;
     } else {
       // There is still more encode, so add the digit and the continuation bit.
       result += base64Digits[0x20 + digit];
     }
   }
   return result;
 }

 export function encodeVlqList(list: number[]) {
   return list.map(encodeVlq).join('');
 }

 // Encode array mappings of the form "compiledLine:compiledColumn => srcFile:srcLine:srcColumn@name"
 // as a source map.
 export function encodeSourceMap(textMap: string[], sourceRoot?: string): SDK.SourceMap.SourceMapV3Object {
   let mappings = '';
   const sources: string[] = [];
   const names: string[] = [];
   let sourcesContent: Array<null|string>|undefined;

   const state = {
     line: -1,
     column: 0,
     srcFile: 0,
     srcLine: 0,
     srcColumn: 0,
     srcName: 0,
   };

   for (const mapping of textMap) {
     let match = mapping.match(/^(\d+):(\d+)(?:\s*=>\s*([^:]+):(\d+):(\d+)(?:@(\S+))?)?$/);
     if (!match) {
       match = mapping.match(/^([^:]+):\s*(.+)$/);
       if (!match) {
         throw new Error(`Cannot parse mapping "${mapping}"`);
       }
       (sourcesContent = sourcesContent ?? [])[getOrAddString(sources, match[1])] = match[2];
       continue;
     }

     const lastState = Object.assign({}, state);
     state.line = Number(match[1]);
     state.column = Number(match[2]);
     const hasSource = match[3] !== undefined;
     const hasName = hasSource && (match[6] !== undefined);
     if (hasSource) {
       state.srcFile = getOrAddString(sources, match[3]);
       state.srcLine = Number(match[4]);
       state.srcColumn = Number(match[5]);
       if (hasName) {
         state.srcName = getOrAddString(names, match[6]);
       }
     }

     if (state.line < lastState.line) {
       throw new Error('Line numbers must be increasing');
     }

     const isNewLine = state.line !== lastState.line;

     if (isNewLine) {
       // Fixup for the first line mapping.
       if (lastState.line === -1) {
         lastState.line = 0;
       }
       // Insert semicolons for all the new lines.
       mappings += ';'.repeat(state.line - lastState.line);
       // Reset the compiled code column counter.
       lastState.column = 0;
     } else {
       mappings += ',';
     }

     // Encode the mapping and add it to the list of mappings.
     const toEncode = [state.column - lastState.column];
     if (hasSource) {
       toEncode.push(
           state.srcFile - lastState.srcFile, state.srcLine - lastState.srcLine, state.srcColumn - lastState.srcColumn);
       if (hasName) {
         toEncode.push(state.srcName - lastState.srcName);
       }
     }
     mappings += encodeVlqList(toEncode);
   }

   const sourceMapV3: SDK.SourceMap.SourceMapV3 = {version: 3, mappings, sources, names};
   if (sourceRoot !== undefined) {
     sourceMapV3.sourceRoot = sourceRoot;
   }
   if (sourcesContent !== undefined) {
     for (let i = 0; i < sources.length; ++i) {
       if (typeof sourcesContent[i] !== 'string') {
         sourcesContent[i] = null;
       }
     }
     sourceMapV3.sourcesContent = sourcesContent;
   }
   return sourceMapV3;

   function getOrAddString(array: string[], s: string) {
     const index = array.indexOf(s);
     if (index >= 0) {
       return index;
     }
     array.push(s);
     return array.length - 1;
   }
 }

 export class OriginalScopeBuilder {
   #encodedScope = '';
   #lastLine = 0;
   #lastKind = 0;

   readonly #names: string[];

   /** The 'names' field of the SourceMap. The builder will modify it. */
   constructor(names: string[]) {
     this.#names = names;
   }

   start(
       line: number, column: number,
       options?: {name?: string, kind?: string, isStackFrame?: boolean, variables?: string[]}): this {
     if (this.#encodedScope !== '') {
       this.#encodedScope += ',';
     }

     const lineDiff = line - this.#lastLine;
     this.#lastLine = line;
     let flags = 0;
     const nameIdxAndKindIdx: number[] = [];

     if (options?.name) {
       flags |= SDK.SourceMapScopes.EncodedOriginalScopeFlag.HAS_NAME;
       nameIdxAndKindIdx.push(this.#nameIdx(options.name));
     }
     if (options?.kind) {
       flags |= SDK.SourceMapScopes.EncodedOriginalScopeFlag.HAS_KIND;
       nameIdxAndKindIdx.push(this.#encodeKind(options?.kind));
     }
     if (options?.isStackFrame) {
       flags |= SDK.SourceMapScopes.EncodedOriginalScopeFlag.IS_STACK_FRAME;
     }

     this.#encodedScope += encodeVlqList([lineDiff, column, flags, ...nameIdxAndKindIdx]);

     if (options?.variables) {
       this.#encodedScope += encodeVlqList(options.variables.map(variable => this.#nameIdx(variable)));
     }

     return this;
   }

   end(line: number, column: number): this {
     if (this.#encodedScope !== '') {
       this.#encodedScope += ',';
     }

     const lineDiff = line - this.#lastLine;
     this.#lastLine = line;
     this.#encodedScope += encodeVlqList([lineDiff, column]);

     return this;
   }

   build(): string {
     const result = this.#encodedScope;
     this.#lastLine = 0;
     this.#encodedScope = '';
     return result;
   }

   #encodeKind(kind: string): number {
     const kindIdx = this.#nameIdx(kind);
     const encodedIdx = kindIdx - this.#lastKind;
     this.#lastKind = kindIdx;
     return encodedIdx;
   }

   #nameIdx(name: string): number {
     let idx = this.#names.indexOf(name);
     if (idx < 0) {
       idx = this.#names.length;
       this.#names.push(name);
     }
     return idx;
   }
 }

 export class GeneratedRangeBuilder {
   #encodedRange = '';
   #state = {
     line: 0,
     column: 0,
     defSourceIdx: 0,
     defScopeIdx: 0,
     callsiteSourceIdx: 0,
     callsiteLine: 0,
     callsiteColumn: 0,
   };

   readonly #names: string[];

   /** The 'names' field of the SourceMap. The builder will modify it. */
   constructor(names: string[]) {
     this.#names = names;
   }

   start(line: number, column: number, options?: {
     isStackFrame?: boolean,
     isHidden?: boolean,
     definition?: {sourceIdx: number, scopeIdx: number},
     callsite?: {sourceIdx: number, line: number, column: number},
     bindings?: Array<string|undefined|Array<{line: number, column: number, name: string|undefined}>>,
   }): this {
     this.#emitLineSeparator(line);
     this.#emitItemSepratorIfRequired();

     const emittedColumn = column - (this.#state.line === line ? this.#state.column : 0);
     this.#encodedRange += encodeVlq(emittedColumn);

     this.#state.line = line;
     this.#state.column = column;

     let flags = 0;
     if (options?.definition) {
       flags |= SDK.SourceMapScopes.EncodedGeneratedRangeFlag.HAS_DEFINITION;
     }
     if (options?.callsite) {
       flags |= SDK.SourceMapScopes.EncodedGeneratedRangeFlag.HAS_CALLSITE;
     }
     if (options?.isStackFrame) {
       flags |= SDK.SourceMapScopes.EncodedGeneratedRangeFlag.IS_STACK_FRAME;
     }
     if (options?.isHidden) {
       flags |= SDK.SourceMapScopes.EncodedGeneratedRangeFlag.IS_HIDDEN;
     }
     this.#encodedRange += encodeVlq(flags);

     if (options?.definition) {
       const {sourceIdx, scopeIdx} = options.definition;
       this.#encodedRange += encodeVlq(sourceIdx - this.#state.defSourceIdx);

       const emittedScopeIdx = scopeIdx - (this.#state.defSourceIdx === sourceIdx ? this.#state.defScopeIdx : 0);
       this.#encodedRange += encodeVlq(emittedScopeIdx);

       this.#state.defSourceIdx = sourceIdx;
       this.#state.defScopeIdx = scopeIdx;
     }

     if (options?.callsite) {
       const {sourceIdx, line, column} = options.callsite;
       this.#encodedRange += encodeVlq(sourceIdx - this.#state.callsiteSourceIdx);

       const emittedLine = line - (this.#state.callsiteSourceIdx === sourceIdx ? this.#state.callsiteLine : 0);
       this.#encodedRange += encodeVlq(emittedLine);

       const emittedColumn = column - (this.#state.callsiteLine === line ? this.#state.callsiteColumn : 0);
       this.#encodedRange += encodeVlq(emittedColumn);

       this.#state.callsiteSourceIdx = sourceIdx;
       this.#state.callsiteLine = line;
       this.#state.callsiteColumn = column;
     }

     for (const bindings of options?.bindings ?? []) {
       if (bindings === undefined || typeof bindings === 'string') {
         this.#encodedRange += encodeVlq(this.#nameIdx(bindings));
         continue;
       }

       this.#encodedRange += encodeVlq(-bindings.length);
       this.#encodedRange += encodeVlq(this.#nameIdx(bindings[0].name));
       if (bindings[0].line !== line || bindings[0].column !== column) {
         throw new Error('First binding line/column must match the range start line/column');
       }

       for (let i = 1; i < bindings.length; ++i) {
         const {line, column, name} = bindings[i];
         const emittedLine = line - bindings[i - 1].line;
         const emittedColumn = column - (line === bindings[i - 1].line ? bindings[i - 1].column : 0);
         this.#encodedRange += encodeVlq(emittedLine);
         this.#encodedRange += encodeVlq(emittedColumn);
         this.#encodedRange += encodeVlq(this.#nameIdx(name));
       }
     }

     return this;
   }

   end(line: number, column: number): this {
     this.#emitLineSeparator(line);
     this.#emitItemSepratorIfRequired();

     const emittedColumn = column - (this.#state.line === line ? this.#state.column : 0);
     this.#encodedRange += encodeVlq(emittedColumn);

     this.#state.line = line;
     this.#state.column = column;

     return this;
   }

   #emitLineSeparator(line: number): void {
     for (let i = this.#state.line; i < line; ++i) {
       this.#encodedRange += ';';
     }
   }

   #emitItemSepratorIfRequired(): void {
     if (this.#encodedRange !== '' && this.#encodedRange[this.#encodedRange.length - 1] !== ';') {
       this.#encodedRange += ',';
     }
   }

   #nameIdx(name?: string): number {
     if (name === undefined) {
       return -1;
     }

     let idx = this.#names.indexOf(name);
     if (idx < 0) {
       idx = this.#names.length;
       this.#names.push(name);
     }
     return idx;
   }

   build(): string {
     const result = this.#encodedRange;
     this.#state = {
       line: 0,
       column: 0,
       defSourceIdx: 0,
       defScopeIdx: 0,
       callsiteSourceIdx: 0,
       callsiteLine: 0,
       callsiteColumn: 0,
     };
     this.#encodedRange = '';
     return result;
   }
 }
	// Copyright 2021 The Chromium Authors. All rights reserved.
	// Use of this source code is governed by a BSD-style license that can be
	// found in the LICENSE file.

	import * as SDK from '../core/sdk/sdk.js';

	const base64Digits = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/';

	export function encodeVlq(n: number): string {
	// Set the sign bit as the least significant bit.
	n = n >= 0 ? 2 * n : 1 - 2 * n;
	// Encode into a base64 run.
	let result = '';
	while (true) {
	// Extract the lowest 5 bits and remove them from the number.
	const digit = n & 0x1f;
	n >>= 5;
	// Is there anything more left to encode?
	if (n === 0) {
	// We are done encoding, finish the run.
	result += base64Digits[digit];
	break;
	} else {
	// There is still more encode, so add the digit and the continuation bit.
	result += base64Digits[0x20 + digit];
	}
	}
	return result;
	}

	export function encodeVlqList(list: number[]) {
	return list.map(encodeVlq).join('');
	}

	// Encode array mappings of the form "compiledLine:compiledColumn => srcFile:srcLine:srcColumn@name"
	// as a source map.
	export function encodeSourceMap(textMap: string[], sourceRoot?: string): SDK.SourceMap.SourceMapV3Object {
	let mappings = '';
	const sources: string[] = [];
	const names: string[] = [];
	let sourcesContent: Array<null\|string>\|undefined;

	const state = {
	line: -1,
	column: 0,
	srcFile: 0,
	srcLine: 0,
	srcColumn: 0,
	srcName: 0,
	};

	for (const mapping of textMap) {
	let match = mapping.match(/^(\d+):(\d+)(?:\s=>\s([^:]+):(\d+):(\d+)(?:@(\S+))?)?$/);
	if (!match) {
	match = mapping.match(/^([^:]+):\s*(.+)$/);
	if (!match) {
	throw new Error(`Cannot parse mapping "${mapping}"`);
	}
	(sourcesContent = sourcesContent ?? [])[getOrAddString(sources, match[1])] = match[2];
	continue;
	}

	const lastState = Object.assign({}, state);
	state.line = Number(match[1]);
	state.column = Number(match[2]);
	const hasSource = match[3] !== undefined;
	const hasName = hasSource && (match[6] !== undefined);
	if (hasSource) {
	state.srcFile = getOrAddString(sources, match[3]);
	state.srcLine = Number(match[4]);
	state.srcColumn = Number(match[5]);
	if (hasName) {
	state.srcName = getOrAddString(names, match[6]);
	}
	}

	if (state.line < lastState.line) {
	throw new Error('Line numbers must be increasing');
	}

	const isNewLine = state.line !== lastState.line;

	if (isNewLine) {
	// Fixup for the first line mapping.
	if (lastState.line === -1) {
	lastState.line = 0;
	}
	// Insert semicolons for all the new lines.
	mappings += ';'.repeat(state.line - lastState.line);
	// Reset the compiled code column counter.
	lastState.column = 0;
	} else {
	mappings += ',';
	}

	// Encode the mapping and add it to the list of mappings.
	const toEncode = [state.column - lastState.column];
	if (hasSource) {
	toEncode.push(
	state.srcFile - lastState.srcFile, state.srcLine - lastState.srcLine, state.srcColumn - lastState.srcColumn);
	if (hasName) {
	toEncode.push(state.srcName - lastState.srcName);
	}
	}
	mappings += encodeVlqList(toEncode);
	}

	const sourceMapV3: SDK.SourceMap.SourceMapV3 = {version: 3, mappings, sources, names};
	if (sourceRoot !== undefined) {
	sourceMapV3.sourceRoot = sourceRoot;
	}
	if (sourcesContent !== undefined) {
	for (let i = 0; i < sources.length; ++i) {
	if (typeof sourcesContent[i] !== 'string') {
	sourcesContent[i] = null;
	}
	}
	sourceMapV3.sourcesContent = sourcesContent;
	}
	return sourceMapV3;

	function getOrAddString(array: string[], s: string) {
	const index = array.indexOf(s);
	if (index >= 0) {
	return index;
	}
	array.push(s);
	return array.length - 1;
	}
	}

	export class OriginalScopeBuilder {
	#encodedScope = '';
	#lastLine = 0;
	#lastKind = 0;

	readonly #names: string[];

	/** The 'names' field of the SourceMap. The builder will modify it. */
	constructor(names: string[]) {
	this.#names = names;
	}

	start(
	line: number, column: number,
	options?: {name?: string, kind?: string, isStackFrame?: boolean, variables?: string[]}): this {
	if (this.#encodedScope !== '') {
	this.#encodedScope += ',';
	}

	const lineDiff = line - this.#lastLine;
	this.#lastLine = line;
	let flags = 0;
	const nameIdxAndKindIdx: number[] = [];

	if (options?.name) {
	flags \|= SDK.SourceMapScopes.EncodedOriginalScopeFlag.HAS_NAME;
	nameIdxAndKindIdx.push(this.#nameIdx(options.name));
	}
	if (options?.kind) {
	flags \|= SDK.SourceMapScopes.EncodedOriginalScopeFlag.HAS_KIND;
	nameIdxAndKindIdx.push(this.#encodeKind(options?.kind));
	}
	if (options?.isStackFrame) {
	flags \|= SDK.SourceMapScopes.EncodedOriginalScopeFlag.IS_STACK_FRAME;
	}

	this.#encodedScope += encodeVlqList([lineDiff, column, flags, ...nameIdxAndKindIdx]);

	if (options?.variables) {
	this.#encodedScope += encodeVlqList(options.variables.map(variable => this.#nameIdx(variable)));
	}

	return this;
	}

	end(line: number, column: number): this {
	if (this.#encodedScope !== '') {
	this.#encodedScope += ',';
	}

	const lineDiff = line - this.#lastLine;
	this.#lastLine = line;
	this.#encodedScope += encodeVlqList([lineDiff, column]);

	return this;
	}

	build(): string {
	const result = this.#encodedScope;
	this.#lastLine = 0;
	this.#encodedScope = '';
	return result;
	}

	#encodeKind(kind: string): number {
	const kindIdx = this.#nameIdx(kind);
	const encodedIdx = kindIdx - this.#lastKind;
	this.#lastKind = kindIdx;
	return encodedIdx;
	}

	#nameIdx(name: string): number {
	let idx = this.#names.indexOf(name);
	if (idx < 0) {
	idx = this.#names.length;
	this.#names.push(name);
	}
	return idx;
	}
	}

	export class GeneratedRangeBuilder {
	#encodedRange = '';
	#state = {
	line: 0,
	column: 0,
	defSourceIdx: 0,
	defScopeIdx: 0,
	callsiteSourceIdx: 0,
	callsiteLine: 0,
	callsiteColumn: 0,
	};

	readonly #names: string[];

	/** The 'names' field of the SourceMap. The builder will modify it. */
	constructor(names: string[]) {
	this.#names = names;
	}

	start(line: number, column: number, options?: {
	isStackFrame?: boolean,
	isHidden?: boolean,
	definition?: {sourceIdx: number, scopeIdx: number},
	callsite?: {sourceIdx: number, line: number, column: number},
	bindings?: Array<string\|undefined\|Array<{line: number, column: number, name: string\|undefined}>>,
	}): this {
	this.#emitLineSeparator(line);
	this.#emitItemSepratorIfRequired();

	const emittedColumn = column - (this.#state.line === line ? this.#state.column : 0);
	this.#encodedRange += encodeVlq(emittedColumn);

	this.#state.line = line;
	this.#state.column = column;

	let flags = 0;
	if (options?.definition) {
	flags \|= SDK.SourceMapScopes.EncodedGeneratedRangeFlag.HAS_DEFINITION;
	}
	if (options?.callsite) {
	flags \|= SDK.SourceMapScopes.EncodedGeneratedRangeFlag.HAS_CALLSITE;
	}
	if (options?.isStackFrame) {
	flags \|= SDK.SourceMapScopes.EncodedGeneratedRangeFlag.IS_STACK_FRAME;
	}
	if (options?.isHidden) {
	flags \|= SDK.SourceMapScopes.EncodedGeneratedRangeFlag.IS_HIDDEN;
	}
	this.#encodedRange += encodeVlq(flags);

	if (options?.definition) {
	const {sourceIdx, scopeIdx} = options.definition;
	this.#encodedRange += encodeVlq(sourceIdx - this.#state.defSourceIdx);

	const emittedScopeIdx = scopeIdx - (this.#state.defSourceIdx === sourceIdx ? this.#state.defScopeIdx : 0);
	this.#encodedRange += encodeVlq(emittedScopeIdx);

	this.#state.defSourceIdx = sourceIdx;
	this.#state.defScopeIdx = scopeIdx;
	}

	if (options?.callsite) {
	const {sourceIdx, line, column} = options.callsite;
	this.#encodedRange += encodeVlq(sourceIdx - this.#state.callsiteSourceIdx);

	const emittedLine = line - (this.#state.callsiteSourceIdx === sourceIdx ? this.#state.callsiteLine : 0);
	this.#encodedRange += encodeVlq(emittedLine);

	const emittedColumn = column - (this.#state.callsiteLine === line ? this.#state.callsiteColumn : 0);
	this.#encodedRange += encodeVlq(emittedColumn);

	this.#state.callsiteSourceIdx = sourceIdx;
	this.#state.callsiteLine = line;
	this.#state.callsiteColumn = column;
	}

	for (const bindings of options?.bindings ?? []) {
	if (bindings === undefined \|\| typeof bindings === 'string') {
	this.#encodedRange += encodeVlq(this.#nameIdx(bindings));
	continue;
	}

	this.#encodedRange += encodeVlq(-bindings.length);
	this.#encodedRange += encodeVlq(this.#nameIdx(bindings[0].name));
	if (bindings[0].line !== line \|\| bindings[0].column !== column) {
	throw new Error('First binding line/column must match the range start line/column');
	}

	for (let i = 1; i < bindings.length; ++i) {
	const {line, column, name} = bindings[i];
	const emittedLine = line - bindings[i - 1].line;
	const emittedColumn = column - (line === bindings[i - 1].line ? bindings[i - 1].column : 0);
	this.#encodedRange += encodeVlq(emittedLine);
	this.#encodedRange += encodeVlq(emittedColumn);
	this.#encodedRange += encodeVlq(this.#nameIdx(name));
	}
	}

	return this;
	}

	end(line: number, column: number): this {
	this.#emitLineSeparator(line);
	this.#emitItemSepratorIfRequired();

	const emittedColumn = column - (this.#state.line === line ? this.#state.column : 0);
	this.#encodedRange += encodeVlq(emittedColumn);

	this.#state.line = line;
	this.#state.column = column;

	return this;
	}

	#emitLineSeparator(line: number): void {
	for (let i = this.#state.line; i < line; ++i) {
	this.#encodedRange += ';';
	}
	}

	#emitItemSepratorIfRequired(): void {
	if (this.#encodedRange !== '' && this.#encodedRange[this.#encodedRange.length - 1] !== ';') {
	this.#encodedRange += ',';
	}
	}

	#nameIdx(name?: string): number {
	if (name === undefined) {
	return -1;
	}

	let idx = this.#names.indexOf(name);
	if (idx < 0) {
	idx = this.#names.length;
	this.#names.push(name);
	}
	return idx;
	}

	build(): string {
	const result = this.#encodedRange;
	this.#state = {
	line: 0,
	column: 0,
	defSourceIdx: 0,
	defScopeIdx: 0,
	callsiteSourceIdx: 0,
	callsiteLine: 0,
	callsiteColumn: 0,
	};
	this.#encodedRange = '';
	return result;
	}
	}