From 875b020e86ee41728c15a6daae3964d93af4e166 Mon Sep 17 00:00:00 2001
From: Albert Meltzer <7529386+kitbellew@users.noreply.github.com>
Date: Sun, 9 Jan 2022 08:31:12 -0800
Subject: [PATCH 1/2] Add side-by-side for-yield and for-do tests

---
 .../src/test/resources/newlines/source_unfold.stat   | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/scalafmt-tests/src/test/resources/newlines/source_unfold.stat b/scalafmt-tests/src/test/resources/newlines/source_unfold.stat
index 68f5c700cc..bfce959ff3 100644
--- a/scalafmt-tests/src/test/resources/newlines/source_unfold.stat
+++ b/scalafmt-tests/src/test/resources/newlines/source_unfold.stat
@@ -655,10 +655,18 @@ def attributes =
 maxColumn = 80
 ===
 val attributes =
- for (i ← 1 to count)
- yield i
+  for (i ← 1 to count) yield i
 >>>
 val attributes = for (i ← 1 to count) yield i
+<<< 2.14 val with short for/do
+maxColumn = 80
+===
+val attributes =
+  for (i ← 1 to count) i * i
+>>>
+val attributes =
+  for (i ← 1 to count)
+    i * i
 <<< 2.15 val with literal apply
 object a {
    val a = b(0x1F, // ID1

From 5c86a924e87c86fbc3bad4be667bfaa1d144f074 Mon Sep 17 00:00:00 2001
From: Albert Meltzer <7529386+kitbellew@users.noreply.github.com>
Date: Sun, 9 Jan 2022 08:18:31 -0800
Subject: [PATCH 2/2] FormatOps: unfold yield correctly and consistently

We were handling it differently in some cases, and inconsistent with
`while` and other `for`.
---
 .../main/scala/org/scalafmt/internal/FormatOps.scala   | 10 ++--------
 .../src/test/resources/newlines/source_unfold.stat     |  4 +++-
 2 files changed, 5 insertions(+), 9 deletions(-)

diff --git a/scalafmt-core/shared/src/main/scala/org/scalafmt/internal/FormatOps.scala b/scalafmt-core/shared/src/main/scala/org/scalafmt/internal/FormatOps.scala
index 213bfc96ff..db798396ae 100644
--- a/scalafmt-core/shared/src/main/scala/org/scalafmt/internal/FormatOps.scala
+++ b/scalafmt-core/shared/src/main/scala/org/scalafmt/internal/FormatOps.scala
@@ -1745,14 +1745,8 @@ class FormatOps(
       def slbSplit(end: T)(implicit fileLine: FileLine) =
         Split(Space, 0).withSingleLine(end, noSyntaxNL = true)
       body match {
-        case _: Term.ForYield =>
-          // unfold policy on yield forces a break
-          // revert it if we are attempting a single line
-          val noBreakOnYield = Policy.before(expire) {
-            case Decision(ft, s) if s.isEmpty && ft.right.is[T.KwYield] =>
-              Seq(Split(Space, 0))
-          }
-          slbSplit(expire).andPolicy(noBreakOnYield)
+        // we force newlines in for/yield
+        case _: Term.ForYield => Split.ignored
         // we force newlines in try/catch/finally
         case _: Term.Try | _: Term.TryWithHandler => Split.ignored
         // don't tuck curried apply
diff --git a/scalafmt-tests/src/test/resources/newlines/source_unfold.stat b/scalafmt-tests/src/test/resources/newlines/source_unfold.stat
index bfce959ff3..5d7ae7ed1d 100644
--- a/scalafmt-tests/src/test/resources/newlines/source_unfold.stat
+++ b/scalafmt-tests/src/test/resources/newlines/source_unfold.stat
@@ -657,7 +657,9 @@ maxColumn = 80
 val attributes =
   for (i ← 1 to count) yield i
 >>>
-val attributes = for (i ← 1 to count) yield i
+val attributes =
+  for (i ← 1 to count)
+    yield i
 <<< 2.14 val with short for/do
 maxColumn = 80
 ===