ts-jest
Version:
A Jest transformer with source map support that lets you use Jest to test projects written in TypeScript
112 lines (111 loc) • 6.03 kB
JavaScript
;
Object.defineProperty(exports, "__esModule", { value: true });
exports.name = exports.version = void 0;
exports.factory = factory;
const bs_logger_1 = require("bs-logger");
/**
* Remember to increase the version whenever transformer's content is changed. This is to inform Jest to not reuse
* the previous cache which contains old transformer's content
*/
exports.version = 4;
// Used for constructing cache key
exports.name = 'hoist-jest';
const HOIST_METHODS = ['mock', 'unmock', 'enableAutomock', 'disableAutomock', 'deepUnmock'];
const JEST_GLOBALS_MODULE_NAME = '@jest/globals';
const JEST_GLOBAL_NAME = 'jest';
function factory({ configSet }) {
const logger = configSet.logger.child({ namespace: exports.name });
const ts = configSet.compilerModule;
const importNamesOfJestObj = [];
const isJestGlobalImport = (node) => {
return (ts.isImportDeclaration(node) &&
ts.isStringLiteral(node.moduleSpecifier) &&
node.moduleSpecifier.text === JEST_GLOBALS_MODULE_NAME);
};
const shouldHoistExpression = (node) => {
if (ts.isCallExpression(node) &&
ts.isPropertyAccessExpression(node.expression) &&
HOIST_METHODS.includes(node.expression.name.text)) {
if (importNamesOfJestObj.length) {
// @jest/globals is in used
return ((ts.isIdentifier(node.expression.expression) &&
importNamesOfJestObj.includes(node.expression.expression.text)) ||
(ts.isPropertyAccessExpression(node.expression.expression) &&
ts.isIdentifier(node.expression.expression.expression) &&
importNamesOfJestObj.includes(node.expression.expression.expression.text)) ||
shouldHoistExpression(node.expression.expression));
}
else {
// @jest/globals is not in used
return ((ts.isIdentifier(node.expression.expression) && node.expression.expression.text === JEST_GLOBAL_NAME) ||
shouldHoistExpression(node.expression.expression));
}
}
return false;
};
/**
* Checks whether given node is a statement that we need to hoist
*/
const isHoistableStatement = (node) => {
return ts.isExpressionStatement(node) && shouldHoistExpression(node.expression);
};
const canHoistInBlockScope = (node) => !!node.statements.find((stmt) => ts.isVariableStatement(stmt) &&
stmt.declarationList.declarations.find((decl) => ts.isIdentifier(decl.name) && decl.name.text !== JEST_GLOBAL_NAME) &&
node.statements.find((stmt) => isHoistableStatement(stmt)));
/**
* Sort statements according to priority
* - Import Jest object from `@jest/globals`
* - Hoistable methods
* - Non-hoistable methods
*/
const sortStatements = (statements) => {
if (statements.length <= 1) {
return statements;
}
return statements.sort((stmtA, stmtB) => isJestGlobalImport(stmtA) ||
(isHoistableStatement(stmtA) && !isHoistableStatement(stmtB) && !isJestGlobalImport(stmtB))
? -1
: 1);
};
const createVisitor = (ctx, _) => {
const visitor = (node) => {
const resultNode = ts.visitEachChild(node, visitor, ctx);
// Since we use `visitEachChild`, we go upwards tree so all children node elements are checked first
if (ts.isBlock(resultNode) && canHoistInBlockScope(resultNode)) {
const newNodeArrayStatements = ts.factory.createNodeArray(sortStatements(resultNode.statements));
return ts.factory.updateBlock(resultNode, newNodeArrayStatements);
}
else {
if (ts.isSourceFile(resultNode)) {
resultNode.statements.forEach((stmt) => {
/**
* Gather all possible import names, from different types of import syntax including:
* - named import, e.g. `import { jest } from '@jest/globals'`
* - aliased named import, e.g. `import {jest as aliasedJest} from '@jest/globals'`
* - namespace import, e.g `import * as JestGlobals from '@jest/globals'`
*/
if (isJestGlobalImport(stmt) &&
stmt.importClause?.namedBindings &&
(ts.isNamespaceImport(stmt.importClause.namedBindings) ||
ts.isNamedImports(stmt.importClause.namedBindings))) {
const { namedBindings } = stmt.importClause;
const jestImportName = ts.isNamespaceImport(namedBindings)
? namedBindings.name.text
: namedBindings.elements.find((element) => element.name.text === JEST_GLOBAL_NAME || element.propertyName?.text === JEST_GLOBAL_NAME)?.name.text;
if (jestImportName) {
importNamesOfJestObj.push(jestImportName);
}
}
});
const newNodeArrayStatements = ts.factory.createNodeArray(sortStatements(resultNode.statements));
importNamesOfJestObj.length = 0;
return ts.factory.updateSourceFile(resultNode, newNodeArrayStatements, resultNode.isDeclarationFile, resultNode.referencedFiles, resultNode.typeReferenceDirectives, resultNode.hasNoDefaultLib, resultNode.libReferenceDirectives);
}
return resultNode;
}
};
return visitor;
};
// returns the transformer factory
return (ctx) => logger.wrap({ [bs_logger_1.LogContexts.logLevel]: bs_logger_1.LogLevels.debug, call: null }, 'visitSourceFileNode(): hoist jest', (sf) => ts.visitNode(sf, createVisitor(ctx, sf)));
}