Allow toggling on/off inline conditionals and loops

src/conditionals.js

@@ -1,4 +1,4 @@
-const { concat, hardline, group, ifBreak, indent, softline } = require("prettier").doc.builders;
+const { breakParent, concat, hardline, group, ifBreak, indent, softline } = require("prettier").doc.builders;
 
 const printWithAddition = (keyword, path, print) => concat([
   `${keyword} `,
@@ -13,7 +13,7 @@ const printTernaryConditions = (keyword, truthyValue, falsyValue) => {
   return keyword === "if" ? parts : parts.reverse();
 };
 
-const printConditional = keyword => (path, print) => {
+const printConditional = keyword => (path, options, print) => {
   const [_predicate, _statements, addition] = path.getValue().body;
 
   // If the addition is not an elsif or an else, then it's the second half of a
@@ -62,6 +62,7 @@ const printConditional = keyword => (path, print) => {
       concat([softline, "end"])
     ]),
     concat([
+      options.inlineConditionals ? "" : breakParent,
       path.call(print, "body", 1),
       ` ${keyword} `,
       path.call(print, "body", 0)

src/index.js

@@ -17,6 +17,20 @@ module.exports = {
       print
     }
   },
+  options: {
+    inlineConditionals: {
+      type: "boolean",
+      category: "Global",
+      default: true,
+      description: "When it fits on one line, allow if and unless statements to use the modifier form."
+    },
+    inlineLoops: {
+      type: "boolean",
+      category: "Global",
+      default: true,
+      description: "When it fits on one line, allow while and until statements to use the modifier form."
+    }
+  },
   defaultOptions: {
     printWidth: 80,
     tabWidth: 2

src/loops.js

@@ -1,19 +1,20 @@
-const { concat, group, hardline, ifBreak, indent, softline } = require("prettier").doc.builders;
+const { breakParent, concat, group, hardline, ifBreak, indent, softline } = require("prettier").doc.builders;
 
-const printLoop = keyword => (path, print) => group(ifBreak(
+const printLoop = keyword => (path, options, print) => group(ifBreak(
   concat([
     concat([`${keyword} `, path.call(print, "body", 0)]),
     indent(concat([softline, path.call(print, "body", 1)])),
     concat([softline, "end"])
   ]),
   concat([
+    options.inlineLoops ? "" : breakParent,
     path.call(print, "body", 1),
     ` ${keyword} `,
     path.call(print, "body", 0)
   ])
 ));
 
-const printFor = (path, print) => group(concat([
+const printFor = (path, options, print) => group(concat([
   path.call(print, "body", 1),
   ".each do |",
   path.call(print, "body", 0),

src/params.js

@@ -1,14 +1,14 @@
 const { concat, group, join } = require("prettier").doc.builders;
 
-const printKwargRestParam = (path, print) => (
+const printKwargRestParam = (path, options, print) => (
   concat(["**", path.call(print, "body", 0)])
 );
 
-const printRestParam = (path, print) => (
+const printRestParam = (path, options, print) => (
   concat(["*", path.call(print, "body", 0)])
 );
 
-const printParams = (path, print) => {
+const printParams = (path, options, print) => {
   const [reqs, opts, rest, post, kwargs, kwarg_rest, block] = path.getValue().body;
   let parts = [];