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denoland-deno/cli/js/compiler_bundler.ts
2020-03-05 18:48:55 +01:00

107 lines
4 KiB
TypeScript

// Copyright 2018-2020 the Deno authors. All rights reserved. MIT license.
import { SYSTEM_LOADER } from "./compiler_bootstrap.ts";
import {
commonPath,
normalizeString,
CHAR_FORWARD_SLASH
} from "./compiler_util.ts";
import { assert } from "./util.ts";
/** Local state of what the root exports are of a root module. */
let rootExports: string[] | undefined;
/** Take a URL and normalize it, resolving relative path parts. */
function normalizeUrl(rootName: string): string {
const match = /^(\S+:\/{2,3})(.+)$/.exec(rootName);
if (match) {
const [, protocol, path] = match;
return `${protocol}${normalizeString(
path,
false,
"/",
code => code === CHAR_FORWARD_SLASH
)}`;
} else {
return rootName;
}
}
/** Given a root name, contents, and source files, enrich the data of the
* bundle with a loader and re-export the exports of the root name. */
export function buildBundle(
rootName: string,
data: string,
sourceFiles: readonly ts.SourceFile[]
): string {
// when outputting to AMD and a single outfile, TypeScript makes up the module
// specifiers which are used to define the modules, and doesn't expose them
// publicly, so we have to try to replicate
const sources = sourceFiles.map(sf => sf.fileName);
const sharedPath = commonPath(sources);
rootName = normalizeUrl(rootName)
.replace(sharedPath, "")
.replace(/\.\w+$/i, "");
// If one of the modules requires support for top-level-await, TypeScript will
// emit the execute function as an async function. When this is the case we
// need to bubble up the TLA to the instantiation, otherwise we instantiate
// synchronously.
const hasTla = data.match(/execute:\sasync\sfunction\s/);
let instantiate: string;
if (rootExports && rootExports.length) {
instantiate = hasTla
? `const __exp = await __instantiateAsync("${rootName}");\n`
: `const __exp = __instantiate("${rootName}");\n`;
for (const rootExport of rootExports) {
if (rootExport === "default") {
instantiate += `export default __exp["${rootExport}"];\n`;
} else {
instantiate += `export const ${rootExport} = __exp["${rootExport}"];\n`;
}
}
} else {
instantiate = hasTla
? `await __instantiateAsync("${rootName}");\n`
: `__instantiate("${rootName}");\n`;
}
return `${SYSTEM_LOADER}\n${data}\n${instantiate}`;
}
/** Set the rootExports which will by the `emitBundle()` */
export function setRootExports(program: ts.Program, rootModule: string): void {
// get a reference to the type checker, this will let us find symbols from
// the AST.
const checker = program.getTypeChecker();
// get a reference to the main source file for the bundle
const mainSourceFile = program.getSourceFile(rootModule);
assert(mainSourceFile);
// retrieve the internal TypeScript symbol for this AST node
const mainSymbol = checker.getSymbolAtLocation(mainSourceFile);
if (!mainSymbol) {
return;
}
rootExports = checker
.getExportsOfModule(mainSymbol)
// .getExportsOfModule includes type only symbols which are exported from
// the module, so we need to try to filter those out. While not critical
// someone looking at the bundle would think there is runtime code behind
// that when there isn't. There appears to be no clean way of figuring that
// out, so inspecting SymbolFlags that might be present that are type only
.filter(
sym =>
sym.flags & ts.SymbolFlags.Class ||
!(
sym.flags & ts.SymbolFlags.Interface ||
sym.flags & ts.SymbolFlags.TypeLiteral ||
sym.flags & ts.SymbolFlags.Signature ||
sym.flags & ts.SymbolFlags.TypeParameter ||
sym.flags & ts.SymbolFlags.TypeAlias ||
sym.flags & ts.SymbolFlags.Type ||
sym.flags & ts.SymbolFlags.Namespace ||
sym.flags & ts.SymbolFlags.InterfaceExcludes ||
sym.flags & ts.SymbolFlags.TypeParameterExcludes ||
sym.flags & ts.SymbolFlags.TypeAliasExcludes
)
)
.map(sym => sym.getName());
}