Add dts bundling

This adds a "small" d.ts bundler script. This script is very basic,
using Node printing to produce its output. Generally speaking, this is
inadvisable as it completely disregards name shadowing, globals, etc.
However, in our case, we don't care about the globals, and we can opt to
restructure our codebase in order to avoid conflict, which we largely
had to do anyway when we were namespaces and everything was in scope.

Gulpfile.mjs

@@ -128,6 +128,19 @@ task("build-src", series(preSrc, buildSrc));
 const cleanSrc = () => cleanProject("src");
 task("clean-src", cleanSrc);
 
+/**
+ * @param {string} entrypoint
+ * @param {string} output
+ */
+async function runDtsBundler(entrypoint, output) {
+    await exec(process.execPath, [
+        "./scripts/dtsBundler.mjs",
+        "--entrypoint",
+        entrypoint,
+        "--output",
+        output,
+    ]);
+}
 
 /** @type {string | undefined} */
 let copyrightHeader;
@@ -275,6 +288,7 @@ const esbuildServices = esbuildTask("./src/typescript/typescript.ts", "./built/l
 const writeServicesCJSShim = () => writeCJSReexport("./built/local/typescript/typescript.js", "./built/local/typescript.js");
 const buildServicesProject = () => buildProject("src/typescript");
 
+// TODO(jakebailey): rename this; no longer "services".
 const buildServices = () => {
     if (cmdLineOptions.bundle) return esbuildServices.build();
     writeServicesCJSShim();
@@ -304,6 +318,9 @@ task("watch-services").flags = {
     "   --built": "Compile using the built version of the compiler."
 };
 
+const dtsServices = () => runDtsBundler("./built/local/typescript/typescript.d.ts", "./built/local/typescript.d.ts");
+task("dts-services", series(preBuild, buildServicesProject, dtsServices));
+task("dts-services").description = "Builds typescript.d.ts";
 
 const esbuildServer = esbuildTask("./src/tsserver/server.ts", "./built/local/tsserver.js", /* exportIsTsObject */ true);
 const writeServerCJSShim = () => writeCJSReexport("./built/local/tsserver/server.js", "./built/local/tsserver.js");
@@ -355,10 +372,11 @@ task("watch-min").flags = {
 const esbuildLssl = esbuildTask("./src/tsserverlibrary/tsserverlibrary.ts", "./built/local/tsserverlibrary.js", /* exportIsTsObject */ true);
 const writeLsslCJSShim = () => writeCJSReexport("./built/local/tsserverlibrary/tsserverlibrary.js", "./built/local/tsserverlibrary.js");
 
+const buildLsslProject = () => buildProject("src/tsserverlibrary");
 const buildLssl = () => {
     if (cmdLineOptions.bundle) return esbuildLssl.build();
     writeLsslCJSShim();
-    return buildProject("src/tsserverlibrary");
+    return buildLsslProject();
 };
 task("lssl", series(preBuild, buildLssl));
 task("lssl").description = "Builds language service server library";
@@ -382,6 +400,14 @@ task("watch-lssl").flags = {
     "   --built": "Compile using the built version of the compiler."
 };
 
+const dtsLssl = () => runDtsBundler("./built/local/tsserverlibrary/tsserverlibrary.d.ts", "./built/local/tsserverlibrary.d.ts");
+task("dts-lssl", series(preBuild, buildLsslProject, dtsLssl));
+task("dts-lssl").description = "Builds tsserverlibrary.d.ts";
+
+// TODO(jakebailey): this is probably not efficient, but, gulp.
+const dts = series(preBuild, parallel(buildServicesProject, buildLsslProject), parallel(dtsServices, dtsLssl));
+task("dts", dts);
+
 const testRunner = "./built/local/run.js";
 const esbuildTests = esbuildTask("./src/testRunner/_namespaces/Harness.ts", testRunner);
 const writeTestsCJSShim = () => writeCJSReexport("./built/local/testRunner/runner.js", testRunner);
@@ -492,7 +518,7 @@ const buildOtherOutputs = parallel(buildCancellationToken, buildTypingsInstaller
 task("other-outputs", series(preBuild, buildOtherOutputs));
 task("other-outputs").description = "Builds miscelaneous scripts and documents distributed with the LKG";
 
-task("local", series(preBuild, parallel(localize, buildTsc, buildServer, buildServices, buildLssl, buildOtherOutputs)));
+task("local", series(preBuild, parallel(localize, buildTsc, buildServer, buildServices, buildLssl, buildOtherOutputs, dts)));
 task("local").description = "Builds the full compiler and services";
 task("local").flags = {
     "   --built": "Compile using the built version of the compiler."
@@ -508,7 +534,7 @@ const preTest = parallel(buildTsc, buildTests, buildServices, buildLssl);
 preTest.displayName = "preTest";
 
 const runTests = () => runConsoleTests(testRunner, "mocha-fivemat-progress-reporter", /*runInParallel*/ false, /*watchMode*/ false);
-task("runtests", series(preBuild, preTest, runTests));
+task("runtests", series(preBuild, preTest, dts, runTests));
 task("runtests").description = "Runs the tests using the built run.js file.";
 task("runtests").flags = {
     "-t --tests=<regex>": "Pattern for tests to run.",
@@ -527,7 +553,7 @@ task("runtests").flags = {
 };
 
 const runTestsParallel = () => runConsoleTests(testRunner, "min", /*runInParallel*/ cmdLineOptions.workers > 1, /*watchMode*/ false);
-task("runtests-parallel", series(preBuild, preTest, runTestsParallel));
+task("runtests-parallel", series(preBuild, preTest, dts, runTestsParallel));
 task("runtests-parallel").description = "Runs all the tests in parallel using the built run.js file.";
 task("runtests-parallel").flags = {
     "   --light": "Run tests in light mode (fewer verifications, but tests run faster).",
@@ -613,8 +639,7 @@ const produceLKG = async () => {
     }
 };
 
-// TODO(jakebailey): dependencies on dts
-task("LKG", series(lkgPreBuild, parallel(localize, buildTsc, buildServer, buildServices, buildLssl, buildOtherOutputs), produceLKG));
+task("LKG", series(lkgPreBuild, parallel(localize, buildTsc, buildServer, buildServices, buildLssl, buildOtherOutputs, dts), produceLKG));
 task("LKG").description = "Makes a new LKG out of the built js files";
 task("LKG").flags = {
     "   --built": "Compile using the built version of the compiler.",