Add support for multiple index signatures

Closes #2470

CHANGELOG.md

@@ -5,6 +5,12 @@
 -   Removed deprecated `navigation.fullTree` option.
 -   API: `MapOptionDeclaration.mapError` has been removed.
 -   API: Deprecated `BindOption` decorator has been removed.
+-   API: `DeclarationReflection.indexSignature` has been renamed to `DeclarationReflection.indexSignatures`.
+    Note: This also affects JSON serialization. TypeDoc will support JSON output from 0.25 until 0.28.
+
+### Bug Fixes
+
+-   TypeDoc now supports objects with multiple index signatures, #2470.
 
 # Unreleased
 

src/lib/converter/comments/declarationReferenceResolver.ts

@@ -177,8 +177,8 @@ function resolveKeyword(
             return (refl as DeclarationReflection).signatures;
 
         case "index":
-            if ((refl as DeclarationReflection).indexSignature) {
-                return [(refl as DeclarationReflection).indexSignature!];
+            if ((refl as DeclarationReflection).indexSignatures) {
+                return (refl as DeclarationReflection).indexSignatures;
             }
             break;
 

src/lib/converter/factories/index-signature.ts

@@ -9,27 +9,22 @@ import {
 import type { Context } from "../context";
 import { ConverterEvents } from "../converter-events";
 
-export function convertIndexSignature(context: Context, symbol: ts.Symbol) {
+export function convertIndexSignatures(context: Context, symbol: ts.Symbol) {
     assert(context.scope instanceof DeclarationReflection);
 
     const indexSymbol = symbol.members?.get("__index" as ts.__String);
-    if (indexSymbol) {
-        // Right now TypeDoc models don't have a way to distinguish between string
-        // and number index signatures... { [x: string]: 1 | 2; [x: number]: 2 }
-        // will be misrepresented.
-        const indexDeclaration = indexSymbol.getDeclarations()?.[0];
-        assert(
-            indexDeclaration &&
-                ts.isIndexSignatureDeclaration(indexDeclaration),
-        );
+    if (!indexSymbol) return;
+
+    for (const indexDeclaration of indexSymbol.getDeclarations() || []) {
+        assert(ts.isIndexSignatureDeclaration(indexDeclaration));
         const param = indexDeclaration.parameters[0];
         assert(param && ts.isParameter(param));
         const index = new SignatureReflection(
             "__index",
             ReflectionKind.IndexSignature,
             context.scope,
         );
-        index.comment = context.getComment(indexSymbol, index.kind);
+        index.comment = context.getNodeComment(indexDeclaration, index.kind);
         index.parameters = [
             new ParameterReflection(
                 param.name.getText(),
@@ -46,7 +41,8 @@ export function convertIndexSignature(context: Context, symbol: ts.Symbol) {
             indexDeclaration.type,
         );
         context.registerReflection(index, indexSymbol);
-        context.scope.indexSignature = index;
+        context.scope.indexSignatures ||= [];
+        context.scope.indexSignatures.push(index);
 
         context.trigger(
             ConverterEvents.CREATE_SIGNATURE,

src/lib/converter/plugins/ImplementsPlugin.ts

@@ -414,7 +414,9 @@ function createLink(
     link(reflection);
     link(reflection.getSignature);
     link(reflection.setSignature);
-    link(reflection.indexSignature);
+    for (const sig of reflection.indexSignatures || []) {
+        link(sig);
+    }
     for (const sig of reflection.signatures ?? []) {
         link(sig);
     }

src/lib/converter/symbols.ts

@@ -18,7 +18,7 @@ import {
 } from "../utils/enum";
 import type { Context } from "./context";
 import { convertDefaultValue } from "./convert-expression";
-import { convertIndexSignature } from "./factories/index-signature";
+import { convertIndexSignatures } from "./factories/index-signature";
 import {
     createConstructSignatureWithType,
     createSignature,
@@ -413,7 +413,7 @@ function convertTypeAliasAsInterface(
     convertConstructSignatures(rc, symbol);
 
     // And finally, index signatures
-    convertIndexSignature(rc, symbol);
+    convertIndexSignatures(rc, symbol);
 }
 
 function convertFunctionOrMethod(
@@ -630,7 +630,7 @@ function convertClassOrInterface(
     convertConstructSignatures(reflectionContext, symbol);
 
     // And finally, index signatures
-    convertIndexSignature(reflectionContext, symbol);
+    convertIndexSignatures(reflectionContext, symbol);
 
     // Normally this shouldn't matter, unless someone did something with skipLibCheck on.
     return ts.SymbolFlags.Alias;

src/lib/converter/types.ts

@@ -31,7 +31,7 @@ import { ReflectionSymbolId } from "../models/reflections/ReflectionSymbolId";
 import { zip } from "../utils/array";
 import type { Context } from "./context";
 import { ConverterEvents } from "./converter-events";
-import { convertIndexSignature } from "./factories/index-signature";
+import { convertIndexSignatures } from "./factories/index-signature";
 import {
     convertParameterNodes,
     convertTypeParameterNodes,
@@ -611,7 +611,7 @@ const typeLiteralConverter: TypeConverter<ts.TypeLiteralNode> = {
             );
         }
 
-        convertIndexSignature(rc, symbol);
+        convertIndexSignatures(rc, symbol);
 
         return new ReflectionType(reflection);
     },
@@ -646,7 +646,7 @@ const typeLiteralConverter: TypeConverter<ts.TypeLiteralNode> = {
         }
 
         if (symbol) {
-            convertIndexSignature(context.withScope(reflection), symbol);
+            convertIndexSignatures(context.withScope(reflection), symbol);
         }
 
         return new ReflectionType(reflection);

src/lib/models/reflections/declaration.ts

@@ -91,7 +91,7 @@ export class DeclarationReflection extends ContainerReflection {
     /**
      * The index signature of this declaration.
      */
-    indexSignature?: SignatureReflection;
+    indexSignatures?: SignatureReflection[];
 
     /**
      * The get signature of this declaration.
@@ -187,8 +187,8 @@ export class DeclarationReflection extends ContainerReflection {
         if (this.signatures) {
             result = result.concat(this.signatures);
         }
-        if (this.indexSignature) {
-            result.push(this.indexSignature);
+        if (this.indexSignatures) {
+            result = result.concat(this.indexSignatures);
         }
         if (this.getSignature) {
             result.push(this.getSignature);
@@ -233,12 +233,9 @@ export class DeclarationReflection extends ContainerReflection {
             }
         }
 
-        if (this.indexSignature) {
+        for (const signature of this.indexSignatures?.slice() || []) {
             if (
-                callback(
-                    this.indexSignature,
-                    TraverseProperty.IndexSignature,
-                ) === false
+                callback(signature, TraverseProperty.IndexSignature) === false
             ) {
                 return;
             }
@@ -298,7 +295,7 @@ export class DeclarationReflection extends ContainerReflection {
             typeParameters: serializer.toObjectsOptional(this.typeParameters),
             type: serializer.toObject(this.type),
             signatures: serializer.toObjectsOptional(this.signatures),
-            indexSignature: serializer.toObject(this.indexSignature),
+            indexSignatures: serializer.toObjectsOptional(this.indexSignatures),
             getSignature: serializer.toObject(this.getSignature),
             setSignature: serializer.toObject(this.setSignature),
             defaultValue: this.defaultValue,
@@ -367,9 +364,17 @@ export class DeclarationReflection extends ContainerReflection {
         this.signatures = de.reviveMany(obj.signatures, (r) =>
             de.constructReflection(r),
         );
-        this.indexSignature = de.revive(obj.indexSignature, (r) =>
-            de.constructReflection(r),
-        );
+
+        // TypeDoc 0.25, remove check with 0.28.
+        if (obj.indexSignature) {
+            this.indexSignatures = [
+                de.revive(obj.indexSignature, (r) => de.constructReflection(r)),
+            ];
+        } else {
+            this.indexSignatures = de.reviveMany(obj.indexSignatures, (r) =>
+                de.constructReflection(r),
+            );
+        }
         this.getSignature = de.revive(obj.getSignature, (r) =>
             de.constructReflection(r),
         );

src/lib/models/reflections/project.ts

@@ -168,7 +168,13 @@ export class ProjectReflection extends ContainerReflection {
             } else if (property === TraverseProperty.GetSignature) {
                 delete parent.getSignature;
             } else if (property === TraverseProperty.IndexSignature) {
-                delete parent.indexSignature;
+                removeIfPresent(
+                    parent.indexSignatures,
+                    reflection as SignatureReflection,
+                );
+                if (!parent.indexSignatures?.length) {
+                    delete parent.indexSignatures;
+                }
             } else if (property === TraverseProperty.Parameters) {
                 removeIfPresent(
                     (reflection.parent as SignatureReflection).parameters,

src/lib/output/themes/default/partials/parameter.tsx

@@ -1,7 +1,7 @@
 import { classNames, getKindClass, wbr } from "../../lib";
 import type { DefaultThemeRenderContext } from "../DefaultThemeRenderContext";
 import { JSX } from "../../../../utils";
-import { DeclarationReflection, ReflectionType } from "../../../../models";
+import { DeclarationReflection, ReflectionType, SignatureReflection } from "../../../../models";
 
 export const parameter = (context: DefaultThemeRenderContext, props: DeclarationReflection) => (
     <>
@@ -26,29 +26,7 @@ export const parameter = (context: DefaultThemeRenderContext, props: Declaration
                     </ul>
                 </li>
             )}
-            {!!props.indexSignature && (
-                <>
-                    <li class="tsd-parameter-index-signature">
-                        <h5>
-                            <span class="tsd-signature-symbol">[</span>
-                            {props.indexSignature?.parameters?.map((item) => (
-                                <>
-                                    {!!item.flags.isRest && <span class="tsd-signature-symbol">...</span>}
-                                    <span class={getKindClass(item)}>{item.name}</span>
-                                    {": "}
-                                    {context.type(item.type)}
-                                </>
-                            ))}
-                            <span class="tsd-signature-symbol">{"]: "}</span>
-                            {context.type(props.indexSignature.type)}
-                        </h5>
-                        {context.commentSummary(props.indexSignature)}
-                        {context.commentTags(props.indexSignature)}
-                        {props.indexSignature.type instanceof ReflectionType &&
-                            context.parameter(props.indexSignature.type.declaration)}
-                    </li>
-                </>
-            )}
+            {props.indexSignatures?.map((index) => renderParamIndexSignature(context, index))}
             {props.children?.map((item) => (
                 <>
                     {item.signatures ? (
@@ -134,3 +112,25 @@ export const parameter = (context: DefaultThemeRenderContext, props: Declaration
         </ul>
     </>
 );
+
+function renderParamIndexSignature(context: DefaultThemeRenderContext, index: SignatureReflection) {
+    return (
+        <li class="tsd-parameter-index-signature">
+            <h5>
+                <span class="tsd-signature-symbol">[</span>
+                {index.parameters!.map((item) => (
+                    <>
+                        <span class={getKindClass(item)}>{item.name}</span>
+                        {": "}
+                        {context.type(item.type)}
+                    </>
+                ))}
+                <span class="tsd-signature-symbol">{"]: "}</span>
+                {context.type(index.type)}
+            </h5>
+            {context.commentSummary(index)}
+            {context.commentTags(index)}
+            {index.type instanceof ReflectionType && context.parameter(index.type.declaration)}
+        </li>
+    );
+}

src/lib/output/themes/default/partials/type.tsx

@@ -394,16 +394,17 @@ const typeRenderers: {
             );
         }
 
-        if (type.declaration.indexSignature) {
-            const index = type.declaration.indexSignature;
-            members.push(
-                <>
-                    [<span class={getKindClass(type.declaration.indexSignature)}>{index.parameters![0].name}</span>:{" "}
-                    {renderType(context, index.parameters![0].type, TypeContext.none)}]
-                    <span class="tsd-signature-symbol">: </span>
-                    {renderType(context, index.type, TypeContext.none)}
-                </>,
-            );
+        if (type.declaration.indexSignatures) {
+            for (const index of type.declaration.indexSignatures) {
+                members.push(
+                    <>
+                        [<span class={getKindClass(index)}>{index.parameters![0].name}</span>:{" "}
+                        {renderType(context, index.parameters![0].type, TypeContext.none)}]
+                        <span class="tsd-signature-symbol">: </span>
+                        {renderType(context, index.type, TypeContext.none)}
+                    </>,
+                );
+            }
         }
 
         if (!members.length && type.declaration.signatures?.length === 1) {

src/lib/output/themes/default/templates/reflection.tsx

@@ -1,7 +1,13 @@
-import { classNames, hasTypeParameters } from "../../lib";
+import { classNames, getKindClass, hasTypeParameters } from "../../lib";
 import type { DefaultThemeRenderContext } from "../DefaultThemeRenderContext";
 import type { PageEvent } from "../../../events";
-import { ContainerReflection, DeclarationReflection, ReflectionKind, ReflectionType } from "../../../../models";
+import {
+    ContainerReflection,
+    DeclarationReflection,
+    ReflectionKind,
+    ReflectionType,
+    SignatureReflection,
+} from "../../../../models";
 import { JSX, Raw } from "../../../../utils";
 
 export function reflectionTemplate(context: DefaultThemeRenderContext, props: PageEvent<ContainerReflection>) {
@@ -55,26 +61,13 @@ export function reflectionTemplate(context: DefaultThemeRenderContext, props: Pa
                             </ul>
                         </section>
                     )}
-                    {!!props.model.signatures && (
+                    {!!props.model.signatures?.length && (
                         <section class="tsd-panel">{context.memberSignatures(props.model)}</section>
                     )}
-                    {!!props.model.indexSignature && (
+                    {!!props.model.indexSignatures?.length && (
                         <section class={classNames({ "tsd-panel": true }, context.getReflectionClasses(props.model))}>
                             <h4 class="tsd-before-signature">{context.i18n.theme_indexable()}</h4>
-                            <div class="tsd-signature">
-                                <span class="tsd-signature-symbol">[</span>
-                                {props.model.indexSignature.parameters!.map((item) => (
-                                    <>
-                                        {item.name}: {context.type(item.type)}
-                                    </>
-                                ))}
-                                <span class="tsd-signature-symbol">]: </span>
-                                {context.type(props.model.indexSignature.type)}
-                            </div>
-                            {context.commentSummary(props.model.indexSignature)}
-                            {context.commentTags(props.model.indexSignature)}
-                            {props.model.indexSignature?.type instanceof ReflectionType &&
-                                context.parameter(props.model.indexSignature.type.declaration)}
+                            {props.model.indexSignatures.map((index) => renderIndexSignature(context, index))}
                         </section>
                     )}
                     {!props.model.signatures && context.memberSources(props.model)}
@@ -85,3 +78,23 @@ export function reflectionTemplate(context: DefaultThemeRenderContext, props: Pa
         </>
     );
 }
+
+function renderIndexSignature(context: DefaultThemeRenderContext, index: SignatureReflection) {
+    return (
+        <>
+            <div class="tsd-signature">
+                <span class="tsd-signature-symbol">[</span>
+                {index.parameters!.map((item) => (
+                    <>
+                        <span class={getKindClass(item)}>{item.name}</span>: {context.type(item.type)}
+                    </>
+                ))}
+                <span class="tsd-signature-symbol">]: </span>
+                {context.type(index.type)}
+            </div>
+            {context.commentSummary(index)}
+            {context.commentTags(index)}
+            {index.type instanceof ReflectionType && context.parameter(index.type.declaration)}
+        </>
+    );
+}

src/lib/serialization/schema.ts

@@ -165,7 +165,7 @@ export interface DeclarationReflection
             | "relevanceBoost"
             | "type"
             | "signatures"
-            | "indexSignature"
+            | "indexSignatures"
             | "defaultValue"
             | "overwrites"
             | "inheritedFrom"
@@ -178,7 +178,10 @@ export interface DeclarationReflection
             | "setSignature"
             | "typeParameters"
             | "readme"
-        > {}
+        > {
+    /** @deprecated moved to {@link indexSignatures} with 0.26. */
+    indexSignature?: SignatureReflection;
+}
 
 /** @category Reflections */
 export interface TypeParameterReflection