microsoft
diff --git a/.devcontainer/Dockerfile b/.devcontainer/Dockerfile
@@ -4,4 +4,4 @@
 ARG VARIANT="14-buster"
 FROM mcr.microsoft.com/vscode/devcontainers/javascript-node:0-${VARIANT}
 
-RUN sudo -u node npm install -g gulp-cli
+RUN sudo -u node npm install -g hereby
diff --git a/.eslintignore b/.eslintignore
@@ -1,5 +1,5 @@
 **/node_modules/**
-/built/local/**
+/built/**
 /tests/**
 /lib/**
 /src/lib/*.generated.d.ts

diff --git a/.eslintrc.json b/.eslintrc.json
@@ -87,7 +87,7 @@
         "local/simple-indent": "error",
         "local/debug-assert": "error",
         "local/no-keywords": "error",
-        "local/one-namespace-per-file": "error",
+        "local/jsdoc-format": "error",
 
         // eslint-plugin-import
         "import/no-extraneous-dependencies": ["error", { "optionalDependencies": false }],

diff --git a/.git-blame-ignore-revs b/.git-blame-ignore-revs
@@ -0,0 +1,8 @@
+# Generated module conversion step - inlineImports
+07758c08ab72481885e662c98d67a0e3a071b032
+# Generated module conversion step - stripNamespaces
+b6c053882696af8ddd94a600429f30584d303d7f
+# Generated module conversion step - explicitify
+9a0b85ce2a3f85f498ab2c05474b4c0b96b111c9
+# Generated module conversion step - unindent
+94724a8c2e68a4c7e267072ca79971f317c45e4a
diff --git a/.github/codeql/codeql-configuration.yml b/.github/codeql/codeql-configuration.yml
@@ -6,3 +6,29 @@ paths:
   - Gulpfile.mjs
 paths-ignore:
   - src/lib
+
+# These queries appear to time out after the module conversion.
+# https://github.com/github/codeql/issues/10937
+query-filters:
+  - exclude:
+      id: js/path-injection # TaintedPath.ql
+  - exclude:
+      id: js/command-line-injection # CommandInjection.ql
+  - exclude:
+      id: js/code-injection # CodeInjection.ql
+  - exclude:
+      id: js/bad-code-sanitization # ImproperCodeSanitization.ql
+  - exclude:
+      id: js/unsafe-dynamic-method-access # UnsafeDynamicMethodAccess.ql
+  - exclude:
+      id: js/clear-text-logging # CleartextLogging.ql
+  - exclude:
+      id: js/regex-injection # RegExpInjection.ql
+  - exclude:
+      id: js/unvalidated-dynamic-method-call # UnvalidatedDynamicMethodCall.ql
+  - exclude:
+      id: js/insecure-download # InsecureDownload.ql
+  - exclude:
+      id: js/prototype-polluting-assignment # PrototypePollutingAssignment.ql
+  - exclude:
+      id: js/request-forgery # RequestForgery.ql
diff --git a/.github/pull_request_template.md b/.github/pull_request_template.md
@@ -4,7 +4,7 @@ Thank you for submitting a pull request!
 Please verify that:
 * [ ] There is an associated issue in the `Backlog` milestone (**required**)
 * [ ] Code is up-to-date with the `main` branch
-* [ ] You've successfully run `gulp runtests` locally
+* [ ] You've successfully run `hereby runtests` locally
 * [ ] There are new or updated unit tests validating the change
 
 Refer to CONTRIBUTING.MD for more details.

diff --git a/.github/workflows/accept-baselines-fix-lints.yaml b/.github/workflows/accept-baselines-fix-lints.yaml
@@ -17,8 +17,8 @@ jobs:
         git config user.name "TypeScript Bot"
         npm install
         git rm -r --quiet tests/baselines/reference :^tests/baselines/reference/docker :^tests/baselines/reference/user
-        gulp runtests-parallel --ci --fix || true
-        gulp baseline-accept
+        npx hereby runtests-parallel --ci --fix || true
+        npx hereby baseline-accept
         git add ./src
         git add ./tests/baselines/reference
         git diff --cached

diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
@@ -21,6 +21,13 @@ jobs:
           - "*"
           - lts/*
           - lts/-1
+        bundle:
+          - "true"
+        include:
+          - node-version: "*"
+            bundle: "false"
+
+    name: Test Node ${{ matrix.node-version }} with --bundle=${{ matrix.bundle }}
 
     steps:
     - uses: actions/checkout@v3
@@ -32,7 +39,7 @@ jobs:
     - run:  npm ci
 
     - name: Tests
-      run:  npm test
+      run:  npm run test -- --bundle=${{ matrix.bundle }}
 
   lint:
     runs-on: ubuntu-latest
@@ -62,11 +69,23 @@ jobs:
     - name: Adding playwright
       run: npm install --no-save --no-package-lock playwright
 
-    - name: Build local
-      run: gulp local
-
     - name: Validate the browser can import TypeScript
-      run: gulp test-browser-integration
+      run: npx hereby test-browser-integration
+
+  typecheck:
+    runs-on: ubuntu-latest
+
+    steps:
+    - uses: actions/checkout@v3
+    - uses: actions/setup-node@v3
+      with:
+        node-version: "*"
+        check-latest: true
+    - run:  npm ci
+
+    - name: Build src
+      run: npx hereby build-src
+
 
   misc:
     runs-on: ubuntu-latest
@@ -80,7 +99,27 @@ jobs:
     - run:  npm ci
 
     - name: Build scripts
-      run: gulp scripts
+      run: npx hereby scripts
 
     - name: ESLint tests
-      run: gulp run-eslint-rules-tests
+      run: npx hereby run-eslint-rules-tests
+
+  self-check:
+    runs-on: ubuntu-latest
+
+    steps:
+    - uses: actions/checkout@v3
+    - uses: actions/setup-node@v3
+      with:
+        node-version: "*"
+        check-latest: true
+    - run:  npm ci
+
+    - name: Build tsc
+      run: npx hereby tsc
+
+    - name: Clean
+      run: npx hereby clean-src
+
+    - name: Self build
+      run: npx hereby build-src --built
diff --git a/.github/workflows/new-release-branch.yaml b/.github/workflows/new-release-branch.yaml
@@ -21,7 +21,7 @@ jobs:
         sed -i -e 's/const versionMajorMinor = ".*"/const versionMajorMinor = "${{ github.event.client_payload.core_major_minor }}"/g' tests/baselines/reference/api/tsserverlibrary.d.ts
         sed -i -e 's/const version\(: string\)\{0,1\} = `${versionMajorMinor}.0-.*`/const version = `${versionMajorMinor}.0-${{ github.event.client_payload.core_tag || 'dev' }}`/g' src/compiler/corePublic.ts
         npm ci
-        gulp LKG
+        npx hereby LKG
         npm test
         git diff
         git add package.json

diff --git a/.github/workflows/nightly.yaml b/.github/workflows/nightly.yaml
@@ -23,10 +23,10 @@ jobs:
       run: |
         npm whoami
         npm ci
-        gulp configure-nightly
-        gulp LKG
-        gulp runtests-parallel
-        gulp clean
+        npx hereby configure-nightly
+        npx hereby LKG
+        npx hereby runtests-parallel
+        npx hereby clean
         npm publish --tag next
       env:
         NODE_AUTH_TOKEN: ${{secrets.npm_token}}
diff --git a/.github/workflows/release-branch-artifact.yaml b/.github/workflows/release-branch-artifact.yaml
@@ -19,11 +19,11 @@ jobs:
     - name: Adding playwright
       run: npm install --no-save --no-package-lock playwright
     - name: Validate the browser can import TypeScript
-      run: gulp test-browser-integration
+      run: npx hereby test-browser-integration
     - name: LKG, clean, and pack
       run: |
-        gulp LKG
-        gulp clean
+        npx hereby LKG
+        npx hereby clean
         npm pack ./
         mv typescript-*.tgz typescript.tgz
     - name: Upload built tarfile

diff --git a/.github/workflows/set-version.yaml b/.github/workflows/set-version.yaml
@@ -27,7 +27,7 @@ jobs:
         sed -i -e 's/const versionMajorMinor = ".*"/const versionMajorMinor = "${{ github.event.client_payload.core_major_minor }}"/g' tests/baselines/reference/api/tsserverlibrary.d.ts
         sed -i -e 's/const version\(: string\)\{0,1\} = .*;/const version = "${{ github.event.client_payload.package_version }}" as string;/g' src/compiler/corePublic.ts
         npm ci
-        gulp LKG
+        npx hereby LKG
         npm test
         git diff
         git add package.json

diff --git a/.github/workflows/update-lkg.yml b/.github/workflows/update-lkg.yml
@@ -16,7 +16,7 @@ jobs:
         git config user.email "typescriptbot@microsoft.com"
         git config user.name "TypeScript Bot"
         npm ci
-        gulp LKG
+        npx hereby LKG
         npm test
         git diff
         git add ./lib

diff --git a/.gulp.js b/.gulp.js
@@ -0,0 +1,19 @@
+const cp = require("child_process");
+const path = require("path");
+const chalk = require("chalk");
+
+const argv = process.argv.slice(2);
+
+// --tasks-simple is used by VS Code to infer a task list; try and keep that working.
+if (!argv.includes("--tasks-simple")) {
+    console.error(chalk.yellowBright("Warning: using gulp shim; please consider running hereby directly."));
+}
+
+const args = [
+    ...process.execArgv,
+    path.join(__dirname, "node_modules", "hereby", "bin", "hereby.js"),
+    ...argv,
+];
+
+const { status } = cp.spawnSync(process.execPath, args, { stdio: "inherit" });
+process.exit(status ?? 1);
diff --git a/.vscode/launch.template.json b/.vscode/launch.template.json
@@ -20,7 +20,6 @@
   "configurations": [
     {
       "type": "node",
-      "protocol": "inspector",
       "request": "launch",
       "name": "Mocha Tests (currently opened test)",
       "runtimeArgs": ["--nolazy"],
@@ -43,20 +42,17 @@
       },
       "sourceMaps": true,
       "smartStep": true,
-      "preLaunchTask": "gulp: tests",
+      "preLaunchTask": "npm: build:tests",
       "console": "integratedTerminal",
-      "outFiles": [
-        "${workspaceRoot}/built/local/run.js"
-      ],
-      "customDescriptionGenerator": "'__tsDebuggerDisplay' in this ? this.__tsDebuggerDisplay(defaultValue) : defaultValue",
+      "customDescriptionGenerator": "'__tsDebuggerDisplay' in this ? this.__tsDebuggerDisplay(defaultValue) : defaultValue"
     },
     {
       // See: https://github.com/microsoft/TypeScript/wiki/Debugging-Language-Service-in-VS-Code
       "type": "node",
       "request": "attach",
       "name": "Attach to VS Code TS Server via Port",
       "processId": "${command:PickProcess}",
-      "customDescriptionGenerator": "'__tsDebuggerDisplay' in this ? this.__tsDebuggerDisplay(defaultValue) : defaultValue",
+      "customDescriptionGenerator": "'__tsDebuggerDisplay' in this ? this.__tsDebuggerDisplay(defaultValue) : defaultValue"
     }
   ]
 }
diff --git a/.vscode/settings.template.json b/.vscode/settings.template.json
@@ -6,4 +6,18 @@
 
     // To use the locally built compiler, after 'npm run build':
     // "typescript.tsdk": "built/local"
+
+    // To ignore commits listed in .git-blame-ignore-revs in GitLens:
+    // "gitlens.advanced.blame.customArguments": [
+    //     "--ignore-revs-file",
+    //     ".git-blame-ignore-revs"
+    // ]
+
+    // These options search the repo recursively and slow down
+    // the build task menu. We define our own in tasks.json.
+    "typescript.tsc.autoDetect": "off",
+    "npm.autoDetect": "off",
+    "grunt.autoDetect": "off",
+    "jake.autoDetect": "off",
+    "gulp.autoDetect": "off"
 }
diff --git a/.vscode/tasks.json b/.vscode/tasks.json
@@ -4,42 +4,51 @@
     "version": "2.0.0",
     "tasks": [
         {
-            "type": "gulp",
-            "label": "gulp: local",
-            "task": "local",
-            "group": {
-                "kind": "build",
-                "isDefault": true
-            },
+            // Kept for backwards compat for old launch.json files so it's
+            // less annoying if moving up to the new build or going back to
+            // the old build.
+            //
+            // This is first because the acutal "npm: build:tests" task
+            // below has the same script value, and VS Code ignores labels
+            // and deduplicates them.
+            // https://github.com/microsoft/vscode/issues/93001
+            "label": "gulp: tests",
+            "type": "npm",
+            "script": "build:tests",
+            "group": "build",
+            "hide": true,
             "problemMatcher": [
                 "$tsc"
             ]
         },
         {
-            "type": "gulp",
-            "label": "gulp: tsc",
-            "task": "tsc",
+            "label": "tsc: watch ./src",
+            "type": "shell",
+            "command": "node",
+            "args": ["${workspaceFolder}/lib/tsc.js", "--build", "${workspaceFolder}/src", "--watch"],
             "group": "build",
+            "isBackground": true,
             "problemMatcher": [
-                "$tsc"
+                "$tsc-watch"
             ]
         },
         {
-            "type": "gulp",
-            "label": "gulp: tests",
-            "task": "tests",
+            "label": "npm: build:compiler",
+            "type": "npm",
+            "script": "build:compiler",
             "group": "build",
             "problemMatcher": [
                 "$tsc"
             ]
         },
         {
-            "type": "gulp",
-            "task": "services",
-            "label": "gulp: services",
+            "label": "npm: build:tests",
+            "type": "npm",
+            "script": "build:tests",
+            "group": "build",
             "problemMatcher": [
                 "$tsc"
-            ],
-        }
+            ]
+        },
     ]
-}
+}