Fix printing of deferred mapped types

sandersn · sandersn · commit 861617006046 · 2018-01-03T15:49:09.000-08:00
A deferred mapped type with a source that has an index signature now
prints {} as the type of the index signature. This avoids an infinite
recursion.
diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts
@@ -2860,8 +2860,11 @@ namespace ts {
                     for (const signature of resolvedType.constructSignatures) {
                         typeElements.push(<ConstructSignatureDeclaration>signatureToSignatureDeclarationHelper(signature, SyntaxKind.ConstructSignature, context));
                     }
-                    if (resolvedType.stringIndexInfo) {
-                        typeElements.push(indexInfoToIndexSignatureDeclarationHelper(resolvedType.stringIndexInfo, IndexKind.String, context));
+                    if (resolvedType.stringIndexInfo && !(resolvedType.objectFlags & ObjectFlags.Deferred)) {
+                        const indexInfo = resolvedType.objectFlags & ObjectFlags.Deferred ?
+                            createIndexInfo(emptyObjectType, resolvedType.stringIndexInfo.isReadonly, resolvedType.stringIndexInfo.declaration) :
+                            resolvedType.stringIndexInfo;
+                        typeElements.push(indexInfoToIndexSignatureDeclarationHelper(indexInfo, IndexKind.String, context));
                     }
                     if (resolvedType.numberIndexInfo) {
                         typeElements.push(indexInfoToIndexSignatureDeclarationHelper(resolvedType.numberIndexInfo, IndexKind.Number, context));

Original file line number	Diff line number	Diff line change
`@@ -2860,8 +2860,11 @@ namespace ts {`
`2860`	`2860`	`for (const signature of resolvedType.constructSignatures) {`
`2861`	`2861`	`typeElements.push(<ConstructSignatureDeclaration>signatureToSignatureDeclarationHelper(signature, SyntaxKind.ConstructSignature, context));`
`2862`	`2862`	`}`
`2863`		`- if (resolvedType.stringIndexInfo) {`
`2864`		`- typeElements.push(indexInfoToIndexSignatureDeclarationHelper(resolvedType.stringIndexInfo, IndexKind.String, context));`
	`2863`	`+ if (resolvedType.stringIndexInfo && !(resolvedType.objectFlags & ObjectFlags.Deferred)) {`
	`2864`	`+ const indexInfo = resolvedType.objectFlags & ObjectFlags.Deferred ?`
	`2865`	`+ createIndexInfo(emptyObjectType, resolvedType.stringIndexInfo.isReadonly, resolvedType.stringIndexInfo.declaration) :`
	`2866`	`+ resolvedType.stringIndexInfo;`
	`2867`	`+ typeElements.push(indexInfoToIndexSignatureDeclarationHelper(indexInfo, IndexKind.String, context));`
`2865`	`2868`	`}`
`2866`	`2869`	`if (resolvedType.numberIndexInfo) {`
`2867`	`2870`	`typeElements.push(indexInfoToIndexSignatureDeclarationHelper(resolvedType.numberIndexInfo, IndexKind.Number, context));`