We were not printing the directives if the body of the function was empty in babylon. Also, we were printing way too many \n
```js
echo "function fn() { 'use strict'; }" | ./bin/prettier.js --stdin
function fn() {
"use strict";
}
```
```js
echo "function fn() { 'use strict'; }" | ./bin/prettier.js --stdin --flow-parser
function fn() {
"use strict";
}
```
Babylon has a bug where it doesn't escape DirectiveLiteral properly. Except for `'use strict';`, this never happens in real world code, so let's put strings in a array in order to workaround this bug and have the same output on both parsers.
https://github.com/babel/babylon/issues/289
DeclareInterface (flow) and InterfaceDeclaration (babylon) are the same type so should behave the same way. I am using the same `declare` trick where I only add it if you are inside of a `declare module` block.
Flow doesn't have a different ast node for `type` and `declare type`. Let's always use the heuristic to be inside of a `declare module` for both ast. This way more snapshot tests are passing between the two parsers.
The search for an empty line incorrectly does +1 which happens to be skipping a `\n`, but in case of windows line endings it skips the `\r` but sees a `\n` afterwards and incorrectly assumes that it is a empty line.
This doesn't change the behavior of doing +1 when there's not a line ending. Making it correct actually triggers a bunch of changes, where half of them are better and half of them regressions. So I'm going to send another pull request to fix that case.
Another issue where babylon and flow ast are different. In babylon, it is NumericLiteral but flow is Literal. All the tests are running on flow so were working correctly, but the default in the command line is to use babylon, so people report bugs with it.
When looking into adding a test, I realized that the logic was inside of bin/prettier.js and therefore only applying to the cli. Moving it to index.js and adding a test so that it's more robust :)
* treat shebang outside of parsing
* use less costly indexOf and reuse format function
* avoid reprinting new line and potential double space at start
* move options back to format function
This is working on the flow parser but not babylon
```js
echo 'class C<T> { submit<T>() { } }' | ./bin/prettier.js --stdin
class C<T> {
submit<T>() {}
}
```
If there you are opting in for double quote but there's a string with a double quote in it, it's better to swap to a single quote to avoid having too many `\`. Note that if there are both single and double quotes in the string, we should use the default string instead.
Fixes#139
Christopher Chedeau