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fix(compiler-cli): produce smaller source maps for templates (#19578)

Assocating each template node with a the generated TypeScript
generated overly verbose source maps. Changed to creating a
source map entry per unique source span instead of each
unique template ast node.

Fixes: #19537

PR Close #19578
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chuckjaz committed Oct 5, 2017
1 parent 81167d9 commit f83989bb0dee71d9b2a5607a6a9d4e7571f6a519
@@ -36,9 +36,10 @@ export class TypeScriptNodeEmitter {
ts.setEmitFlags(commentStmt, ts.EmitFlags.CustomPrologue);
preambleStmts.push(commentStmt);
}
const newSourceFile = ts.updateSourceFileNode(
sourceFile,
[...preambleStmts, ...converter.getReexports(), ...converter.getImports(), ...statements]);
const sourceStatments =
[...preambleStmts, ...converter.getReexports(), ...converter.getImports(), ...statements];
converter.updateSourceMap(sourceStatments);
const newSourceFile = ts.updateSourceFileNode(sourceFile, sourceStatments);
return [newSourceFile, converter.getNodeMap()];
}
}
@@ -63,7 +64,6 @@ function createLiteral(value: any) {
*/
class _NodeEmitterVisitor implements StatementVisitor, ExpressionVisitor {
private _nodeMap = new Map<ts.Node, Node>();
private _mapped = new Set<Node>();
private _importsWithPrefixes = new Map<string, string>();
private _reexports = new Map<string, {name: string, as: string}[]>();
private _templateSources = new Map<ParseSourceFile, ts.SourceMapSource>();
@@ -92,17 +92,49 @@ class _NodeEmitterVisitor implements StatementVisitor, ExpressionVisitor {
getNodeMap() { return this._nodeMap; }
private record<T extends ts.Node>(ngNode: Node, tsNode: T|null): RecordedNode<T> {
if (tsNode && !this._nodeMap.has(tsNode)) {
this._nodeMap.set(tsNode, ngNode);
if (!this._mapped.has(ngNode)) {
this._mapped.add(ngNode);
updateSourceMap(statements: ts.Statement[]) {
let lastRangeStartNode: ts.Node|undefined = undefined;
let lastRangeEndNode: ts.Node|undefined = undefined;
let lastRange: ts.SourceMapRange|undefined = undefined;
const recordLastSourceRange = () => {
if (lastRange && lastRangeStartNode && lastRangeEndNode) {
if (lastRangeStartNode == lastRangeEndNode) {
ts.setSourceMapRange(lastRangeEndNode, lastRange);
} else {
ts.setSourceMapRange(lastRangeStartNode, lastRange);
// Only emit the pos for the first node emitted in the range.
ts.setEmitFlags(lastRangeStartNode, ts.EmitFlags.NoTrailingSourceMap);
ts.setSourceMapRange(lastRangeEndNode, lastRange);
// Only emit emit end for the last node emitted in the range.
ts.setEmitFlags(lastRangeEndNode, ts.EmitFlags.NoLeadingSourceMap);
}
}
};
const visitNode = (tsNode: ts.Node) => {
const ngNode = this._nodeMap.get(tsNode);
if (ngNode) {
const range = this.sourceRangeOf(ngNode);
if (range) {
ts.setSourceMapRange(tsNode, range);
if (!lastRange || range.source != lastRange.source || range.pos != lastRange.pos ||
range.end != lastRange.end) {
recordLastSourceRange();
lastRangeStartNode = tsNode;
lastRange = range;
}
lastRangeEndNode = tsNode;
}
}
ts.forEachChild(tsNode, child => this.record(ngNode, tsNode));
ts.forEachChild(tsNode, visitNode);
};
statements.forEach(visitNode);
recordLastSourceRange();
}
private record<T extends ts.Node>(ngNode: Node, tsNode: T|null): RecordedNode<T> {
if (tsNode && !this._nodeMap.has(tsNode)) {
this._nodeMap.set(tsNode, ngNode);
}
return tsNode as RecordedNode<T>;
}
@@ -419,6 +419,19 @@ describe('TypeScriptNodeEmitter', () => {
return result;
}
function mappingItemsOf(text: string): MappingItem[] {
// find the source map:
const sourceMapMatch = /sourceMappingURL\=data\:application\/json;base64,(.*)$/.exec(text);
const sourceMapBase64 = sourceMapMatch ![1];
const sourceMapBuffer = Buffer.from(sourceMapBase64, 'base64');
const sourceMapText = sourceMapBuffer.toString('utf8');
const sourceMap: RawSourceMap = JSON.parse(sourceMapText);
const consumer = new SourceMapConsumer(sourceMap);
const mappings: MappingItem[] = [];
consumer.eachMapping(mapping => { mappings.push(mapping); });
return mappings;
}
it('should produce a source map that maps back to the source', () => {
const statement = someVar.set(o.literal(1)).toDeclStmt();
const text = '<my-comp> a = 1 </my-comp>';
@@ -430,16 +443,8 @@ describe('TypeScriptNodeEmitter', () => {
statement.sourceSpan = new ParseSourceSpan(start, end);
const result = emitStmt(statement);
const mappings = mappingItemsOf(result);
// find the source map:
const sourceMapMatch = /sourceMappingURL\=data\:application\/json;base64,(.*)$/.exec(result);
const sourceMapBase64 = sourceMapMatch ![1];
const sourceMapBuffer = Buffer.from(sourceMapBase64, 'base64');
const sourceMapText = sourceMapBuffer.toString('utf8');
const sourceMap: RawSourceMap = JSON.parse(sourceMapText);
const consumer = new SourceMapConsumer(sourceMap);
const mappings: MappingItem[] = [];
consumer.eachMapping(mapping => { mappings.push(mapping); });
expect(mappings).toEqual([
{
source: sourceUrl,
@@ -459,9 +464,45 @@ describe('TypeScriptNodeEmitter', () => {
}
]);
});
it('should produce a mapping per range instead of a mapping per node', () => {
const text = '<my-comp> a = 1 </my-comp>';
const sourceName = '/some/file.html';
const sourceUrl = '../some/file.html';
const file = new ParseSourceFile(text, sourceName);
const start = new ParseLocation(file, 0, 0, 0);
const end = new ParseLocation(file, text.length, 0, text.length);
const stmt = (loc: number) => {
const start = new ParseLocation(file, loc, 0, loc);
const end = new ParseLocation(file, loc + 1, 0, loc + 1);
const span = new ParseSourceSpan(start, end);
return someVar
.set(new o.BinaryOperatorExpr(
o.BinaryOperator.Plus, o.literal(loc, null, span), o.literal(loc, null, span), null,
span))
.toDeclStmt();
};
const stmts = [1, 2, 3, 4, 5, 6].map(stmt);
const result = emitStmt(stmts);
const mappings = mappingItemsOf(result);
// The span is used in three different nodes but should only be emitted at most twice
// (once for the start and once for the end of a span).
const maxDup = Math.max(
...Array.from(countsOfDuplicatesMap(mappings.map(m => m.originalColumn)).values()));
expect(maxDup <= 2).toBeTruthy('A redundant range was emitted');
});
});
});
function countsOfDuplicatesMap<T>(a: T[]): Map<T, number> {
const result = new Map<T, number>();
for (const item of a) {
result.set(item, (result.get(item) || 0) + 1);
}
return result;
}
const FILES: Directory = {
somePackage: {'someGenFile.ts': `export var a: number;`}
};

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