NODE-2716, NODE-2718, NODE-2719, NODE-2721: Convert to Typescript (#388)

This is the first stage of converting the entire codebase over to
TypeScript. The goals of this step were to preserve history as
well as functional output of the compilation step. Here is a
summary of the commits involved:

 - move all files to `src`, preserving history
   this also maintains a copy of the original js source in the `lib`
   folder (without history) so we can compare the transpiled output
   for potential issues
 - add type information to all types
 - move entry point `bson.ts` to `src` folder for ease of future testing
 - run tests against transpiled module code
 - fix all linting issues with ts conversion
 - fix running manual tests with ts codebase
 - ensure we run the ts pipeline before publish
 - bump typescript version, fix last outstanding issue
 - `prepublishOnly` => `prepare`

NODE-2716, NODE-2718, NODE-2719, NODE-2721

Author: nbbeeken

.eslintignore

@@ -0,0 +1,4 @@
+dist/
+node_modules/
+docs/
+types/

.eslintrc

@@ -0,0 +1,43 @@
+{
+  "root": true,
+  "extends": [
+    "eslint:recommended",
+    "plugin:prettier/recommended",
+    "plugin:@typescript-eslint/eslint-recommended",
+    "plugin:@typescript-eslint/recommended",
+    "prettier/@typescript-eslint"
+  ],
+  "env": {
+    "node": true
+  },
+  "globals": {
+    "Promise": true,
+    "Uint8Array": true,
+    "ArrayBuffer": true,
+    "Set": true,
+    "Map": false
+  },
+  "parserOptions": {
+    "ecmaVersion": 2017
+  },
+  "plugins": [
+    "prettier"
+  ],
+  "rules": {
+    "prettier/prettier": "error",
+    "no-console": "off",
+    "eqeqeq": [
+      "error",
+      "always",
+      {
+        "null": "ignore"
+      }
+    ],
+    "strict": [
+      "error",
+      "global"
+    ],
+    "@typescript-eslint/ban-types": "off",
+    "@typescript-eslint/no-var-requires": "off"
+  }
+}

.eslintrc.json

@@ -71,6 +71,16 @@ functions:
           ${PREPARE_SHELL}
           echo "NODE_VERSION=${NODE_VERSION} TEST_TARGET=${TEST_TARGET}"
           NODE_VERSION=${NODE_VERSION} ${PROJECT_DIRECTORY}/.evergreen/run-tests.sh ${TEST_TARGET}
+  run checks:
+    - command: shell.exec
+      type: test
+      params:
+        working_dir: src
+        script: |
+          ${PREPARE_SHELL}
+          echo "NODE_VERSION=${NODE_VERSION} TEST_TARGET=${TEST_TARGET}"
+          bash ${PROJECT_DIRECTORY}/.evergreen/run-checks.sh
+
 
 tasks:
   - name: node-tests-v6
@@ -133,6 +143,15 @@ tasks:
       - func: run tests
         vars:
           TEST_TARGET: browser
+  - name: run-checks
+    tags:
+      - run-checks
+    commands:
+      - func: fetch source
+        vars:
+          NODE_MAJOR_VERSION: 12
+      - func: install dependencies
+      - func: run checks
 
 buildvariants:
   - name: linux
@@ -147,3 +166,8 @@ buildvariants:
     display_name: Windows 64
     run_on: windows-64-vsMulti-small
     tasks: [".node"]
+  - name: lint
+    display_name: lint
+    run_on: rhel70
+    tasks:
+      - run-checks

.evergreen/config.yml

@@ -41,14 +41,16 @@ path: $NVM_SYMLINK
 EOT
 
   nvm install ${NODE_VERSION}
+  nvm install 10.22.0 # install lts for compilation only
   nvm on
 else
   curl -o- $NVM_URL | bash
   [ -s "${NVM_DIR}/nvm.sh" ] && \. "${NVM_DIR}/nvm.sh"
 
   nvm install --no-progress ${NODE_VERSION}
+  nvm install --no-progress 10.22.0 # install lts for compilation only
 fi
-nvm use ${NODE_VERSION}
+nvm use 10.22.0 # use lts for setup, runtime node can be different
 
 # setup npm cache in a local directory
 cat <<EOT > .npmrc
@@ -60,4 +62,5 @@ registry=https://registry.npmjs.org
 EOT
 
 # install node dependencies
-npm install
+npm install # npm prepare runs after install and will compile the library
+nvm use ${NODE_VERSION} # Switch to the node version we want to test against

.evergreen/install-dependencies.sh

@@ -0,0 +1,9 @@
+#!/bin/bash
+set -o errexit  # Exit the script with error if any of the commands fail
+
+export PROJECT_DIRECTORY="$(pwd)"
+NODE_ARTIFACTS_PATH="${PROJECT_DIRECTORY}/node-artifacts"
+export NVM_DIR="${NODE_ARTIFACTS_PATH}/nvm"
+[ -s "$NVM_DIR/nvm.sh" ] && \. "$NVM_DIR/nvm.sh"
+
+npm run lint

.evergreen/run-checks.sh

@@ -18,10 +18,10 @@ fi
 
 case $1 in
   "node")
-    npm run lint && npm run test-node
+    npm run test-node
     ;;
   "browser")
-    npm run lint && npm run test-browser
+    npm run test-browser
     ;;
   *)
     npm test

.evergreen/run-tests.sh

@@ -15,3 +15,11 @@ builderror.log
 
 bson.sublime-project
 bson.sublime-workspace
+
+lib
+types/
+.nyc_output/
+coverage/
+*.d.ts
+*.tgz
+docs/public

.gitignore

@@ -0,0 +1,13 @@
+{
+  "extension": [
+    "js"
+  ],
+  "require": [
+    "ts-node/register",
+    "chai/register-expect",
+    "source-map-support/register"
+  ],
+  "timeout": 10000,
+  "throw-deprecation": true,
+  "parallel": false
+}

.mocharc.json

@@ -0,0 +1,5 @@
+{
+  "extends": "@istanbuljs/nyc-config-typescript",
+  "include": ["src/**/*.ts"],
+  "reporter": ["lcovonly", "text-summary"]
+}