Class ObjectVariable

src/adapter/variableStore.ts:884–975

const NoCustomStringRepr = Symbol('NoStringRepr');

class ObjectVariable extends Variable implements IMemoryReadable {
  constructor(
    context: VariableContext,
    remoteObject: Cdp.Runtime.RemoteObject,
    private customStringRepr?: string | typeof NoCustomStringRepr,
  ) {
    super(context, remoteObject);
  }

  public override async toDap(
    previewContext: PreviewContextType,
    valueFormat?: Dap.ValueFormat,
  ): Promise<Dap.Variable> {
    const [parentDap, value] = await Promise.all([
      await super.toDap(previewContext, valueFormat),
      await this.getValueRepresentation(previewContext),
    ]);

    return {
      ...parentDap,
      type: this.remoteObject.className || this.remoteObject.subtype || this.remoteObject.type,
      variablesReference: this.id,
      memoryReference: memoryReadableTypes.has(this.remoteObject.subtype)
        ? String(this.id)
        : undefined,
      value,
    };
  }

  private async getValueRepresentation(previewContext: PreviewContextType) {
    if (typeof this.customStringRepr === 'string') {
      return this.customStringRepr;
    }

    // for the first level of evaluations, toString it on-demand
    if (
      !this.context.parent
      && this.remoteObject.objectId
      && this.customStringRepr !== NoCustomStringRepr
    ) {
      try {
        const ret = await this.context.cdp.Runtime.callFunctionOn({
          functionDeclaration: getToStringIfCustom.decl(
            `${customStringReprMaxLength}`,
            this.context.customDescriptionGenerator || 'null',
          ),
          objectId: this.remoteObject.objectId,
          returnByValue: true,
        });
        if (ret?.result.value) {
          return (this.customStringRepr = localizeIndescribable(ret.result.value));
        }
      } catch (e) {
        this.customStringRepr = NoCustomStringRepr;
        // ignored
      }
    }