fixup! Rework if statements

src/Nixfmt/Pretty.hs

@@ -206,7 +206,8 @@ absorbIn x                         = line <> group x <> line
 -- Only absorb "else if"
 absorbElse :: Expression -> Doc
 absorbElse (If if_ cond then_ expr0 else_ expr1)
-    = hardspace <> pretty if_ <> hardspace <> group cond <> hardspace
+    -- `if cond then` if it fits on one line, otherwise `if\n  cond\nthen` (with cond indented)
+    = hardspace <> (group (pretty if_ <> hardspace <> line' <> nest 2 (group cond) <> hardspace <> line'))
       <> pretty then_ <> absorbThen expr0
       <> pretty else_ <> absorbElse expr1
 -- XXX Same as for Then
@@ -245,7 +246,7 @@ instance Pretty Expression where
     pretty (If if_ cond then_ expr0 else_ expr1)
         = base $ group $
             -- `if cond then` if it fits on one line, otherwise `if\n  cond\nthen` (with cond indented)
-            pretty if_ <> hardspace <> line' <> nest 2 (group cond) <> hardspace <> line'
+            (group (pretty if_ <> hardspace <> line' <> nest 2 (group cond) <> hardspace <> line'))
             <> pretty then_ <> absorbThen expr0
             <> pretty else_ <> absorbElse expr1
 

test/diff/idioms_lib_1/out.nix

@@ -6,8 +6,7 @@
     msg:
     # Value to return
     x:
-    if
-      pred
+    if pred
     then
       trace msg x
     else

test/diff/idioms_lib_2/out.nix

@@ -94,26 +94,23 @@ rec {
 
   # bitwise “and”
   bitAnd = builtins.bitAnd or (import ./zip-int-bits.nix (a: b:
-    if
-      a == 1 && b == 1
+    if a == 1 && b == 1
     then
       1
     else
       0));
 
   # bitwise “or”
   bitOr = builtins.bitOr or (import ./zip-int-bits.nix (a: b:
-    if
-      a == 1 || b == 1
+    if a == 1 || b == 1
     then
       1
     else
       0));
 
   # bitwise “xor”
   bitXor = builtins.bitXor or (import ./zip-int-bits.nix (a: b:
-    if
-      a != b
+    if a != b
     then
       1
     else
@@ -131,8 +128,7 @@ rec {
      Type: boolToString :: bool -> string
   */
   boolToString = b:
-    if
-      b
+    if b
     then
       "true"
     else
@@ -176,8 +172,7 @@ rec {
     f:
     # Argument to check for null before passing it to `f`
     a:
-    if
-      a == null
+    if a == null
     then
       a
     else
@@ -217,8 +212,7 @@ rec {
   # Returns the current nixpkgs version suffix as string.
   versionSuffix = let
     suffixFile = ../.version-suffix;
-  in if
-    pathExists suffixFile
+  in if pathExists suffixFile
   then
     lib.strings.fileContents suffixFile
   else
@@ -235,11 +229,11 @@ rec {
     let
       revisionFile = "${toString ./..}/.git-revision";
       gitRepo = "${toString ./..}/.git";
-    in if
-      lib.pathIsGitRepo gitRepo
+    in if lib.pathIsGitRepo gitRepo
     then
       lib.commitIdFromGitRepo gitRepo
-    else if lib.pathExists revisionFile then
+    else if lib.pathExists revisionFile
+    then
       lib.fileContents revisionFile
     else
       default;
@@ -258,17 +252,15 @@ rec {
 
   # Return minimum of two numbers.
   min = x: y:
-    if
-      x < y
+    if x < y
     then
       x
     else
       y;
 
   # Return maximum of two numbers.
   max = x: y:
-    if
-      x > y
+    if x > y
     then
       x
     else
@@ -293,11 +285,11 @@ rec {
      a > b,  compare a b => 1
   */
   compare = a: b:
-    if
-      a < b
+    if a < b
     then
       -1
-    else if a > b then
+    else if a > b
+    then
       1
     else
       0;
@@ -331,16 +323,15 @@ rec {
     a:
     # Second value to compare
     b:
-    if
-      p a
+    if p a
     then
-      if
-        p b
+      if p b
       then
         yes a b
       else
         -1
-    else if p b then
+    else if p b
+    then
       1
     else
       no a b;
@@ -399,8 +390,7 @@ rec {
      Type: bool -> string -> a -> a
   */
   warnIf = cond: msg:
-    if
-      cond
+    if cond
     then
       warn msg
     else
@@ -425,8 +415,7 @@ rec {
          pkgs
   */
   throwIfNot = cond: msg:
-    if
-      cond
+    if cond
     then
       x: x
     else
@@ -482,8 +471,7 @@ rec {
      setFunctionArgs : (a → b) → Map String Bool.
   */
   functionArgs = f:
-    if
-      f ? __functor
+    if f ? __functor
     then
       f.__functionArgs or (lib.functionArgs (f.__functor f))
     else
@@ -507,8 +495,7 @@ rec {
   toHexString = i:
     let
       toHexDigit = d:
-        if
-          d < 10
+        if d < 10
         then
           toString d
         else
@@ -536,8 +523,7 @@ rec {
   toBaseDigits = base: i:
     let
       go = i:
-        if
-          i < base
+        if i < base
         then [ i ] else
           let
             r = i - ((i / base) * base);