function _mapType()

in src/assembler.ts [2218:2252]
35 lines of code
8 McCabe index (conditional complexity)

    function _mapType(this: Assembler): spec.CollectionTypeReference {
      let elementtype: spec.TypeReference;
      const objectType = type.getStringIndexType();
      if (objectType) {
        elementtype = this._typeReference(objectType, declaration, 'map element type');
      } else {
        const typeDecl = type.symbol.declarations?.[0];
        if (
          typeDecl != null &&
          ts.isTypeLiteralNode(typeDecl) &&
          typeDecl.members.length == 1 &&
          ts.isIndexSignatureDeclaration(typeDecl.members[0]) &&
          typeDecl.members[0].parameters[0].type != null &&
          ts.isTemplateLiteralTypeNode(typeDecl.members[0].parameters[0].type)
        ) {
          const indexTypeNode = typeDecl.members[0].type;
          const indexType = this._typeChecker.getTypeFromTypeNode(indexTypeNode);
          elementtype = this._typeReference(indexType, indexTypeNode, 'map element type');
        } else {
          this._diagnostics.push(
            JsiiDiagnostic.JSII_1003_UNSUPPORTED_TYPE.create(
              declaration,
              'Only string-indexed map types are supported',
            ),
          );
          elementtype = spec.CANONICAL_ANY;
        }
      }
      return {
        collection: {
          elementtype,
          kind: spec.CollectionKind.Map,
        },
      };
    }