Add Flow

.babelrc

@@ -2,7 +2,8 @@
   "plugins": [
     ["transform-builtin-extend", { "globals": ["Date"] }],
     "transform-class-properties",
-    "transform-es2015-classes"
+    "transform-es2015-classes",
+    "transform-flow-strip-types"
   ],
   "presets":  [
     "stage-0",

.drone.yml

@@ -7,6 +7,9 @@ build:
     commands:
       - npm i -g yarn
       - yarn
+      ## libelf1 is needed to run flow
+      - apt-get update -qq && apt-get install -qy libelf1
+      - npm run flow
       - npm run lint
       - npm test
 

.flowconfig

@@ -0,0 +1,8 @@
+[ignore]
+
+[include]
+
+[libs]
+
+[options]
+suppress_comment= \\(.\\|\n\\)*\\$FlowIgnore

flow-typed/npm/babel-cli_vx.x.x.js

@@ -0,0 +1,108 @@
+// flow-typed signature: 4d76b5103c79c4871e27d79020c34d75
+// flow-typed version: <<STUB>>/babel-cli_v^6.11.4/flow_v0.37.4
+
+/**
+ * This is an autogenerated libdef stub for:
+ *
+ *   'babel-cli'
+ *
+ * Fill this stub out by replacing all the `any` types.
+ *
+ * Once filled out, we encourage you to share your work with the 
+ * community by sending a pull request to: 
+ * https://github.com/flowtype/flow-typed
+ */
+
+declare module 'babel-cli' {
+  declare module.exports: any;
+}
+
+/**
+ * We include stubs for each file inside this npm package in case you need to
+ * require those files directly. Feel free to delete any files that aren't
+ * needed.
+ */
+declare module 'babel-cli/bin/babel-doctor' {
+  declare module.exports: any;
+}
+
+declare module 'babel-cli/bin/babel-external-helpers' {
+  declare module.exports: any;
+}
+
+declare module 'babel-cli/bin/babel-node' {
+  declare module.exports: any;
+}
+
+declare module 'babel-cli/bin/babel' {
+  declare module.exports: any;
+}
+
+declare module 'babel-cli/lib/_babel-node' {
+  declare module.exports: any;
+}
+
+declare module 'babel-cli/lib/babel-external-helpers' {
+  declare module.exports: any;
+}
+
+declare module 'babel-cli/lib/babel-node' {
+  declare module.exports: any;
+}
+
+declare module 'babel-cli/lib/babel/dir' {
+  declare module.exports: any;
+}
+
+declare module 'babel-cli/lib/babel/file' {
+  declare module.exports: any;
+}
+
+declare module 'babel-cli/lib/babel/index' {
+  declare module.exports: any;
+}
+
+declare module 'babel-cli/lib/babel/util' {
+  declare module.exports: any;
+}
+
+// Filename aliases
+declare module 'babel-cli/bin/babel-doctor.js' {
+  declare module.exports: $Exports<'babel-cli/bin/babel-doctor'>;
+}
+declare module 'babel-cli/bin/babel-external-helpers.js' {
+  declare module.exports: $Exports<'babel-cli/bin/babel-external-helpers'>;
+}
+declare module 'babel-cli/bin/babel-node.js' {
+  declare module.exports: $Exports<'babel-cli/bin/babel-node'>;
+}
+declare module 'babel-cli/bin/babel.js' {
+  declare module.exports: $Exports<'babel-cli/bin/babel'>;
+}
+declare module 'babel-cli/index' {
+  declare module.exports: $Exports<'babel-cli'>;
+}
+declare module 'babel-cli/index.js' {
+  declare module.exports: $Exports<'babel-cli'>;
+}
+declare module 'babel-cli/lib/_babel-node.js' {
+  declare module.exports: $Exports<'babel-cli/lib/_babel-node'>;
+}
+declare module 'babel-cli/lib/babel-external-helpers.js' {
+  declare module.exports: $Exports<'babel-cli/lib/babel-external-helpers'>;
+}
+declare module 'babel-cli/lib/babel-node.js' {
+  declare module.exports: $Exports<'babel-cli/lib/babel-node'>;
+}
+declare module 'babel-cli/lib/babel/dir.js' {
+  declare module.exports: $Exports<'babel-cli/lib/babel/dir'>;
+}
+declare module 'babel-cli/lib/babel/file.js' {
+  declare module.exports: $Exports<'babel-cli/lib/babel/file'>;
+}
+declare module 'babel-cli/lib/babel/index.js' {
+  declare module.exports: $Exports<'babel-cli/lib/babel/index'>;
+}
+declare module 'babel-cli/lib/babel/util.js' {
+  declare module.exports: $Exports<'babel-cli/lib/babel/util'>;
+}

flow-typed/npm/babel-core_vx.x.x.js

@@ -0,0 +1,192 @@
+// flow-typed signature: ac28d744323eadd55d2ad2588d34e2df
+// flow-typed version: <<STUB>>/babel-core_v^6.21.0/flow_v0.37.4
+
+/**
+ * This is an autogenerated libdef stub for:
+ *
+ *   'babel-core'
+ *
+ * Fill this stub out by replacing all the `any` types.
+ *
+ * Once filled out, we encourage you to share your work with the 
+ * community by sending a pull request to: 
+ * https://github.com/flowtype/flow-typed
+ */
+
+declare module 'babel-core' {
+  declare module.exports: any;
+}
+
+/**
+ * We include stubs for each file inside this npm package in case you need to
+ * require those files directly. Feel free to delete any files that aren't
+ * needed.
+ */
+declare module 'babel-core/lib/api/browser' {
+  declare module.exports: any;
+}
+
+declare module 'babel-core/lib/api/node' {
+  declare module.exports: any;
+}
+
+declare module 'babel-core/lib/helpers/merge' {
+  declare module.exports: any;
+}
+
+declare module 'babel-core/lib/helpers/normalize-ast' {
+  declare module.exports: any;
+}
+
+declare module 'babel-core/lib/helpers/resolve' {
+  declare module.exports: any;
+}
+
+declare module 'babel-core/lib/store' {
+  declare module.exports: any;
+}
+
+declare module 'babel-core/lib/tools/build-external-helpers' {
+  declare module.exports: any;
+}
+
+declare module 'babel-core/lib/transformation/file/index' {
+  declare module.exports: any;
+}
+
+declare module 'babel-core/lib/transformation/file/logger' {
+  declare module.exports: any;
+}
+
+declare module 'babel-core/lib/transformation/file/metadata' {
+  declare module.exports: any;
+}
+
+declare module 'babel-core/lib/transformation/file/options/build-config-chain' {
+  declare module.exports: any;
+}
+
+declare module 'babel-core/lib/transformation/file/options/config' {
+  declare module.exports: any;
+}
+
+declare module 'babel-core/lib/transformation/file/options/index' {
+  declare module.exports: any;
+}
+
+declare module 'babel-core/lib/transformation/file/options/option-manager' {
+  declare module.exports: any;
+}
+
+declare module 'babel-core/lib/transformation/file/options/parsers' {
+  declare module.exports: any;
+}
+
+declare module 'babel-core/lib/transformation/file/options/removed' {
+  declare module.exports: any;
+}
+
+declare module 'babel-core/lib/transformation/internal-plugins/block-hoist' {
+  declare module.exports: any;
+}
+
+declare module 'babel-core/lib/transformation/internal-plugins/shadow-functions' {
+  declare module.exports: any;
+}
+
+declare module 'babel-core/lib/transformation/pipeline' {
+  declare module.exports: any;
+}
+
+declare module 'babel-core/lib/transformation/plugin-pass' {
+  declare module.exports: any;
+}
+
+declare module 'babel-core/lib/transformation/plugin' {
+  declare module.exports: any;
+}
+
+declare module 'babel-core/lib/util' {
+  declare module.exports: any;
+}
+
+declare module 'babel-core/register' {
+  declare module.exports: any;
+}
+
+// Filename aliases
+declare module 'babel-core/index' {
+  declare module.exports: $Exports<'babel-core'>;
+}
+declare module 'babel-core/index.js' {
+  declare module.exports: $Exports<'babel-core'>;
+}
+declare module 'babel-core/lib/api/browser.js' {
+  declare module.exports: $Exports<'babel-core/lib/api/browser'>;
+}
+declare module 'babel-core/lib/api/node.js' {
+  declare module.exports: $Exports<'babel-core/lib/api/node'>;
+}
+declare module 'babel-core/lib/helpers/merge.js' {
+  declare module.exports: $Exports<'babel-core/lib/helpers/merge'>;
+}
+declare module 'babel-core/lib/helpers/normalize-ast.js' {
+  declare module.exports: $Exports<'babel-core/lib/helpers/normalize-ast'>;
+}
+declare module 'babel-core/lib/helpers/resolve.js' {
+  declare module.exports: $Exports<'babel-core/lib/helpers/resolve'>;
+}
+declare module 'babel-core/lib/store.js' {
+  declare module.exports: $Exports<'babel-core/lib/store'>;
+}
+declare module 'babel-core/lib/tools/build-external-helpers.js' {
+  declare module.exports: $Exports<'babel-core/lib/tools/build-external-helpers'>;
+}
+declare module 'babel-core/lib/transformation/file/index.js' {
+  declare module.exports: $Exports<'babel-core/lib/transformation/file/index'>;
+}
+declare module 'babel-core/lib/transformation/file/logger.js' {
+  declare module.exports: $Exports<'babel-core/lib/transformation/file/logger'>;
+}
+declare module 'babel-core/lib/transformation/file/metadata.js' {
+  declare module.exports: $Exports<'babel-core/lib/transformation/file/metadata'>;
+}
+declare module 'babel-core/lib/transformation/file/options/build-config-chain.js' {
+  declare module.exports: $Exports<'babel-core/lib/transformation/file/options/build-config-chain'>;
+}
+declare module 'babel-core/lib/transformation/file/options/config.js' {
+  declare module.exports: $Exports<'babel-core/lib/transformation/file/options/config'>;
+}
+declare module 'babel-core/lib/transformation/file/options/index.js' {
+  declare module.exports: $Exports<'babel-core/lib/transformation/file/options/index'>;
+}
+declare module 'babel-core/lib/transformation/file/options/option-manager.js' {
+  declare module.exports: $Exports<'babel-core/lib/transformation/file/options/option-manager'>;
+}
+declare module 'babel-core/lib/transformation/file/options/parsers.js' {
+  declare module.exports: $Exports<'babel-core/lib/transformation/file/options/parsers'>;
+}
+declare module 'babel-core/lib/transformation/file/options/removed.js' {
+  declare module.exports: $Exports<'babel-core/lib/transformation/file/options/removed'>;
+}
+declare module 'babel-core/lib/transformation/internal-plugins/block-hoist.js' {
+  declare module.exports: $Exports<'babel-core/lib/transformation/internal-plugins/block-hoist'>;
+}
+declare module 'babel-core/lib/transformation/internal-plugins/shadow-functions.js' {
+  declare module.exports: $Exports<'babel-core/lib/transformation/internal-plugins/shadow-functions'>;
+}
+declare module 'babel-core/lib/transformation/pipeline.js' {
+  declare module.exports: $Exports<'babel-core/lib/transformation/pipeline'>;
+}
+declare module 'babel-core/lib/transformation/plugin-pass.js' {
+  declare module.exports: $Exports<'babel-core/lib/transformation/plugin-pass'>;
+}
+declare module 'babel-core/lib/transformation/plugin.js' {
+  declare module.exports: $Exports<'babel-core/lib/transformation/plugin'>;
+}
+declare module 'babel-core/lib/util.js' {
+  declare module.exports: $Exports<'babel-core/lib/util'>;
+}
+declare module 'babel-core/register.js' {
+  declare module.exports: $Exports<'babel-core/register'>;
+}