gatsby-source-prismic/src/runtime/normalize.ts

Gatsby source plugin for building websites using Prismic as a data source

import * as prismicT from "@prismicio/types";

import { PrismicSpecialType } from "../types";

import * as normalizers from "./normalizers";
import {
	NormalizedValue,
	StructuredTextField,
	NormalizeConfig as BaseNormalizeConfig,
	NormalizerDependencies,
} from "./types";

function assertType<T>(
	type:
		| prismicT.CustomTypeModelFieldType
		| prismicT.CustomTypeModelSliceType
		| PrismicSpecialType,
	guard: (value: unknown) => boolean,
	value: unknown,
): asserts value is T {
	if (!guard(value)) {
		throw new Error(`Value is not expected type ${type}`);
	}
}

type NormalizeConfig<Value> = BaseNormalizeConfig<Value> &
	NormalizerDependencies;

export const normalize = <Value>(
	config: NormalizeConfig<Value>,
): NormalizedValue<Value> => {
	const type = config.getTypePath(config.path);
	if (!type) {
		throw new Error(
			`No type for path: ${config.path.join(
				".",
			)}. Did you register the Custom Type model?`,
		);
	}

	switch (type.type) {
		case PrismicSpecialType.Document: {
			assertType<prismicT.PrismicDocument>(
				PrismicSpecialType.Document,
				normalizers.isDocument,
				config.value,
			);

			return normalizers.document({
				...config,
				value: config.value,
			}) as NormalizedValue<Value>;
		}

		case PrismicSpecialType.DocumentData: {
			assertType<prismicT.PrismicDocument["data"]>(
				PrismicSpecialType.DocumentData,
				normalizers.isDocumentDataField,
				config.value,
			);

			return normalizers.documentData({
				...config,
				value: config.value,
			}) as NormalizedValue<Value>;
		}

		case prismicT.CustomTypeModelFieldType.Group: {
			assertType<prismicT.GroupField>(
				prismicT.CustomTypeModelFieldType.Group,
				normalizers.isGroupField,
				config.value,
			);

			return normalizers.group({
				...config,
				value: config.value,
			}) as NormalizedValue<Value>;
		}

		case prismicT.CustomTypeModelFieldType.Slices: {
			assertType<prismicT.SliceZone>(
				prismicT.CustomTypeModelFieldType.Slices,
				normalizers.isSlices,
				config.value,
			);

			return normalizers.slices({
				...config,
				value: config.value,
			}) as NormalizedValue<Value>;
		}

		case prismicT.CustomTypeModelSliceType.Slice:
		case PrismicSpecialType.SharedSliceVariation: {
			assertType<prismicT.Slice | prismicT.SharedSlice>(
				prismicT.CustomTypeModelSliceType.Slice,
				normalizers.isSlice,
				config.value,
			);

			return normalizers.slice({
				...config,
				value: config.value,
			}) as NormalizedValue<Value>;
		}

		case prismicT.CustomTypeModelFieldType.Link: {
			assertType<prismicT.LinkField>(
				prismicT.CustomTypeModelFieldType.Link,
				normalizers.isLinkField,
				config.value,
			);

			return normalizers.link({
				value: config.value,
				path: config.path,
				getNode: config.getNode,
				linkResolver: config.linkResolver,
			}) as NormalizedValue<Value>;
		}

		case prismicT.CustomTypeModelFieldType.Image: {
			assertType<prismicT.ImageField>(
				prismicT.CustomTypeModelFieldType.Image,
				normalizers.isImageField,
				config.value,
			);

			return normalizers.image({
				value: config.value,
				path: config.path,
				imageImgixParams: config.imageImgixParams,
				imagePlaceholderImgixParams: config.imagePlaceholderImgixParams,
			}) as NormalizedValue<Value>;
		}

		case prismicT.CustomTypeModelFieldType.StructuredText: {
			assertType<StructuredTextField>(
				prismicT.CustomTypeModelFieldType.StructuredText,
				normalizers.isStructuredTextField,
				config.value,
			);

			return normalizers.structuredText({
				value: config.value,
				path: config.path,
				linkResolver: config.linkResolver,
				htmlSerializer: config.htmlSerializer,
			}) as NormalizedValue<Value>;
		}

		default: {
			return config.value as NormalizedValue<Value>;
		}
	}
};