Support using Babel 7 for internal code compilation.

[orta]

Well, this was simple. I updated a bunch of our versions, both 6 + 7 exists in Danger's dev dependency stack (as Jest brought 6 in, which is fine.)

This PR means Babel handles both JavaScript, and TypeScript. It's relatively trivial in terms of danger's implementation. Kinda amazing that something that has taken so much time is so trivial to work with as a consumer.

I'm not 100% that I'm getting the default options, don't want to accidentally kick off a project's plugins just to ensure flow/ts is added. However, all tests are passing locally. 👍

[DangerCI]

	Warnings
⚠️	New dependencies added: @types/lodash.includes, babel-core, babel-plugin-transform-typescript and babel-traverse.
⚠️	Could not get info from npm on @types/lodash.includes

yarn why @types/lodash.includes output

• Has been hoisted to "@types/lodash.includes"
• This module exists because it's specified in "devDependencies".
• Disk size without dependencies: "16kB"
• Disk size with unique dependencies: "1.7MB"
• Disk size with transitive dependencies: "1.7MB"
• Amount of shared dependencies: 1

babel-core

Author: Sebastian McKenzie

Description: Babel compiler core.

Homepage: https://babeljs.io/

Created	over 2 years ago
Last Updated	3 days ago
License	MIT
Maintainers	5
Releases	249
Direct Dependencies	babel-code-frame, babel-generator, babel-helpers, babel-messages, babel-register, babel-runtime, babel-template, babel-traverse, babel-types, babylon, convert-source-map, debug, json5, lodash, minimatch, path-is-absolute, private, slash and source-map
Keywords	6to5, babel, classes, const, es6, harmony, let, modules, transpile, transpiler, var, babel-core and compiler

README

# babel-core

Babel compiler core.

var babel = require("babel-core");
import { transform } from 'babel-core';
import * as babel from 'babel-core';

All transformations will use your local configuration files (.babelrc or in package.json). See options to disable it.

babel.transform(code: string, options?: Object)

Transforms the passed in code. Returning an object with the generated code,
source map, and AST.

babel.transform(code, options) // => { code, map, ast }

Example

var result = babel.transform("code();", options);
result.code;
result.map;
result.ast;

babel.transformFile(filename: string, options?: Object, callback: Function)

Asynchronously transforms the entire contents of a file.

babel.transformFile(filename, options, callback)

Example

babel.transformFile("filename.js", options, function (err, result) {
  result; // => { code, map, ast }
});

babel.transformFileSync(filename: string, options?: Object)

Synchronous version of babel.transformFile. Returns the transformed contents of
the filename.

babel.transformFileSync(filename, options) // => { code, map, ast }

Example

babel.transformFileSync("filename.js", options).code;

babel.transformFromAst(ast: Object, code?: string, options?: Object)

Given, an AST, transform it.

const code = "if (true) return;";
const ast = babylon.parse(code, { allowReturnOutsideFunction: true });
const { code, map, ast } = babel.transformFromAst(ast, code, options);

Options

Babel CLI

You can pass these options from the Babel CLI like so:

babel --name=value

Following is a table of the options you can use:

Option	Default	Description
ast	true	Include the AST in the returned object
auxiliaryCommentAfter	null	Attach a comment after all non-user injected code.
auxiliaryCommentBefore	null	Attach a comment before all non-user injected code.
babelrc	true	Specify whether or not to use .babelrc and .babelignore files. Not available when using the CLI, use --no-babelrc instead.
code	true	Enable code generation
comments	true	Output comments in generated output.
compact	"auto"	Do not include superfluous whitespace characters and line terminators. When set to "auto" compact is set to true on input sizes of >500KB.
env	{}	This is an object of keys that represent different environments. For example, you may have: { env: { production: { /* specific options */ } } } which will use those options when the environment variable BABEL_ENV is set to "production". If BABEL_ENV isn't set then NODE_ENV will be used, if it's not set then it defaults to "development"
extends	null	A path to an .babelrc file to extend
filename	"unknown"	Filename for use in errors etc.
filenameRelative	(filename)	Filename relative to sourceRoot.
generatorOpts	{}	An object containing the options to be passed down to the babel code generator, babel-generator
getModuleId	null	Specify a custom callback to generate a module id with. Called as getModuleId(moduleName). If falsy value is returned then the generated module id is used.
highlightCode	true	ANSI highlight syntax error code frames
ignore	null	Opposite to the only option. ignore is disregarded if only is specified.
inputSourceMap	null	A source map object that the output source map will be based on.
minified	false	Should the output be minified (not printing last semicolons in blocks, printing literal string values instead of escaped ones, stripping () from new when safe)
moduleId	null	Specify a custom name for module ids.
moduleIds	false	If truthy, insert an explicit id for modules. By default, all modules are anonymous. (Not available for common modules)
moduleRoot	(sourceRoot)	Optional prefix for the AMD module formatter that will be prepend to the filename on module definitions.
only	null	A glob, regex, or mixed array of both, matching paths to only compile. Can also be an array of arrays containing paths to explicitly match. When attempting to compile a non-matching file it's returned verbatim.
parserOpts	{}	An object containing the options to be passed down to the babel parser, babylon
plugins	[]	List of plugins to load and use.
presets	[]	List of presets (a set of plugins) to load and use.
retainLines	false	Retain line numbers. This will lead to wacky code but is handy for scenarios where you can't use source maps. (NOTE: This will not retain the columns)
resolveModuleSource	null	Resolve a module source ie. import "SOURCE"; to a custom value. Called as resolveModuleSource(source, filename).
shouldPrintComment	null	An optional callback that controls whether a comment should be output or not. Called as shouldPrintComment(commentContents). NOTE: This overrides the comment option when used.
sourceFileName	(filenameRelative)	Set sources[0] on returned source map.
sourceMaps	false	If truthy, adds a map property to returned output. If set to "inline", a comment with a sourceMappingURL directive is added to the bottom of the returned code. If set to "both" then a map property is returned as well as a source map comment appended. This does not emit sourcemap files by itself! To have sourcemaps emitted using the CLI, you must pass it the --source-maps option.
sourceMapTarget	(filenameRelative)	Set file on returned source map.
sourceRoot	(moduleRoot)	The root from which all sources are relative.
sourceType	"module"	Indicate the mode the code should be parsed in. Can be either "script" or "module".
wrapPluginVisitorMethod	null	An optional callback that can be used to wrap visitor methods. NOTE: This is useful for things like introspection, and not really needed for implementing anything. Called as wrapPluginVisitorMethod(pluginAlias, visitorType, callback).

yarn why babel-core output

• Has been hoisted to "babel-core"
• This module exists because it's specified in "devDependencies".
• Disk size without dependencies: "304kB"
• Disk size with unique dependencies: "8.33MB"
• Disk size with transitive dependencies: "9.59MB"
• Amount of shared dependencies: 38

babel-plugin-transform-typescript

Author: Unknown

Description: Transform TypeScript into ES.next

Homepage: http://npmjs.com/package/babel-plugin-transform-typescript

Created	12 days ago
Last Updated	12 days ago
License	MIT
Maintainers	1
Releases	1
Direct Dependencies	babel-plugin-syntax-typescript
Keywords	babel-plugin and typescript

README

# babel-plugin-transform-typescript

Transform TypeScript into ES.next.

Does not type-check its input. For that, you will need to install and set up TypeScript.

Does not support namespaces or const enums because those require type information to transpile.
Also does not support export = and import =, because those cannot be transpiled to ES.next.

Example

In

const x: number = 0;

Out

const x = 0;

Installation

npm install --save-dev babel-plugin-transform-typescript

Usage

Via .babelrc (Recommended)

.babelrc

{
  "plugins": ["transform-typescript"]
}

Via CLI

babel --plugins transform-typescript script.js

Via Node API

require("babel-core").transform("code", {
  plugins: ["transform-typescript"]
});

yarn why babel-plugin-transform-typescript output

• Has been hoisted to "babel-plugin-transform-typescript"
• This module exists because it's specified in "devDependencies".
• Disk size without dependencies: "36kB"
• Disk size with unique dependencies: "56kB"
• Disk size with transitive dependencies: "56kB"
• Amount of shared dependencies: 1

Generated by 🚫 dangerJS

[orta]

The above was a hack because the inferred type for lodash.includes was object: collection, target: any, fromIndex?:any, somethingElse:any having a extra mandatory 4th param.

By adding @types/lodash.include it went to object: collection, target: any, fromIndex?:any.

[orta]

Fixing the types above from includes highlighted that danger.git.diffForFile("changelog.md") actually returns a Promise. An older pre-release version of the API was probably synchronous. A good catch 👍

[macklinu]

Will this require dangerfile.ts users to include a .babelrc with this transform in order for the TypeScript dangerfile to be evaluated?

[macklinu]

Before this PR, all that was needed was a project to include the typescript dependency, and the dangerfile.ts could be parsed, right? My question is, is this no longer the case?

[orta]

Yeh, I thought about this for a bit, and came to the same conclusion. So I started work on bringing back the original typescript optional dep also - so you can have TypeScript via tsc, or Babel, and then optionally babel for JS. All depending on if the deps exist.

[hzoo]

Aside: you can use preset-env and remove es2015, syntax,transform-regenerator (you'll need 2.0.0-alpha.19 since it's another repo still)

[orta]

Thanks @hzoo - going to call this an atomic PR for now, I've made an issue about updating to the env preset ( I gave it a shot and it didn't pass tests, so I'll give myself a bit more time to figure it out later. )