@storybook/addon-svelte-csf/dist/parser/extract/svelte/module-nodes.js

Allows to write stories in Svelte syntax

import pkg from '@storybook/addon-svelte-csf/package.json' with { type: 'json' };
import { DefaultOrNamespaceImportUsedError, MissingDefineMetaImportError, MissingDefineMetaVariableDeclarationError, MissingModuleTagError, NoStoryComponentDestructuredError, } from '../../../utils/error/parser/extract/svelte.js';
const AST_NODES_NAMES = {
    defineMeta: 'defineMeta',
    Story: 'Story',
};
/**
 * Extract Svelte AST nodes via `svelte.compile`,
 * and from the module tag - `<script module>`.
 * They are needed for further code analysis/transformation.
 */
export async function extractModuleNodes(options) {
    const { module, filename } = options;
    if (!module) {
        throw new MissingModuleTagError(filename);
    }
    const { walk } = await import('zimmerframe');
    const state = {};
    const visitors = {
        ImportDeclaration(node, { state, visit }) {
            const { source, specifiers } = node;
            if (source.value === pkg.name) {
                for (const specifier of specifiers) {
                    if (specifier.type !== 'ImportSpecifier') {
                        throw new DefaultOrNamespaceImportUsedError(filename);
                    }
                    visit(specifier, state);
                }
            }
        },
        ImportSpecifier(node) {
            if ('name' in node.imported && node.imported.name === AST_NODES_NAMES.defineMeta) {
                state.defineMetaImport = node;
            }
        },
        VariableDeclaration(node, { state }) {
            const { declarations } = node;
            const declaration = declarations[0];
            const { id, init } = declaration;
            if (id.type === 'ObjectPattern' &&
                init?.type === 'CallExpression' &&
                init.callee.type === 'Identifier' &&
                init.callee.name === state.defineMetaImport?.local.name) {
                state.defineMetaVariableDeclaration = node;
                for (const property of id.properties) {
                    if (property.type === 'Property' &&
                        property.key.type === 'Identifier' &&
                        property.key.name === AST_NODES_NAMES.Story &&
                        property.value.type === 'Identifier') {
                        state.storyIdentifier = property.value;
                    }
                }
            }
        },
    };
    walk(module.content, state, visitors);
    const { defineMetaImport, defineMetaVariableDeclaration, storyIdentifier } = state;
    if (!defineMetaImport) {
        throw new MissingDefineMetaImportError(filename);
    }
    if (!defineMetaVariableDeclaration) {
        throw new MissingDefineMetaVariableDeclarationError(filename);
    }
    if (!storyIdentifier) {
        throw new NoStoryComponentDestructuredError({ filename, defineMetaImport });
    }
    return {
        defineMetaImport,
        defineMetaVariableDeclaration,
        storyIdentifier,
    };
}