Add break in each case alt in js backend (#1796)

* Add `break` in each case alt in js backend
Fixes #1795

* Remove some uneeded `break`s

* linter

* Follow @stefan-hoeck 's advice
This is neater
Note: I renamed breakAfterAssignment because it's too much work to type

* [ test ] Test for #1795

* cleanup: remove unneeded vcat

src/Compiler/ES/Codegen.idr

@@ -583,6 +583,10 @@ lambdaArgs : List Var -> Doc
 lambdaArgs [] = "()" <+> lambdaArrow
 lambdaArgs xs = hcat $ (<+> lambdaArrow) . var <$> xs
 
+insertBreak : (r : Effect) -> (Doc, Doc) -> (Doc, Doc)
+insertBreak Returns x = x
+insertBreak (ErrorWithout _) (pat, exp) = (pat, vcat [exp, "break;"])
+
 mutual
   -- converts an `Exp` to JS code
   exp : {auto c : Ref ESs ESSt} -> Exp -> Core Doc
@@ -610,28 +614,31 @@ mutual
   stmt (Declare v s) =
     (\d => vcat ["let" <++> var v <+> ";",d]) <$> stmt s
   stmt (Assign v x) =
-    (\d => vcat [hcat [var v,softEq,d,";"], "break;"]) <$> exp x
+    (\d => hcat [var v,softEq,d,";"]) <$> exp x
 
   stmt (ConSwitch r sc alts def) = do
-    as <- traverse alt alts
+    as <- traverse (map (insertBreak r) . alt) alts
     d  <- traverseOpt stmt def
     pure $  switch (minimal sc <+> ".h") as d
-    where alt : EConAlt r -> Core (Doc,Doc)
-          alt (MkEConAlt _ RECORD b)  = ("undefined",) <$> stmt b
-          alt (MkEConAlt _ NIL b)     = ("0",) <$> stmt b
-          alt (MkEConAlt _ CONS b)    = ("undefined",) <$> stmt b
-          alt (MkEConAlt _ NOTHING b) = ("0",) <$> stmt b
-          alt (MkEConAlt _ JUST b)    = ("undefined",) <$> stmt b
-          alt (MkEConAlt t _ b)       = (tag2es t,) <$> stmt b
+    where
+        alt : {r : _} -> EConAlt r -> Core (Doc,Doc)
+        alt (MkEConAlt _ RECORD b)  = ("undefined",) <$> stmt b
+        alt (MkEConAlt _ NIL b)     = ("0",) <$> stmt b
+        alt (MkEConAlt _ CONS b)    = ("undefined",) <$> stmt b
+        alt (MkEConAlt _ NOTHING b) = ("0",) <$> stmt b
+        alt (MkEConAlt _ JUST b)    = ("undefined",) <$> stmt b
+        alt (MkEConAlt t _ b)       = (tag2es t,) <$> stmt b
 
   stmt (ConstSwitch r sc alts def) = do
-    as <- traverse alt alts
+    as <- traverse (map (insertBreak r) . alt) alts
     d  <- traverseOpt stmt def
     ex <- exp sc
     pure $ switch ex as d
-    where alt : EConstAlt r -> Core (Doc,Doc)
-          alt (MkEConstAlt c b) = do d    <- stmt b
-                                     pure (Text $ jsConstant c, d)
+    where
+        alt : EConstAlt r -> Core (Doc,Doc)
+        alt (MkEConstAlt c b) = do
+            d <- stmt b
+            pure (Text $ jsConstant c, d)
 
   stmt (Error x)   = pure $ jsCrashExp (jsStringDoc x) <+> ";"
   stmt (Block ss s) = do

tests/Main.idr

@@ -251,7 +251,7 @@ nodeTests = MkTestPool "Node backend" [] (Just Node)
     [ "node001", "node002", "node003", "node004", "node005", "node006"
     , "node007", "node008", "node009", "node011", "node012", "node015"
     , "node017", "node018", "node019", "node021", "node022", "node023"
-    , "node024", "node025"
+    , "node024", "node025", "node026"
     , "perf001"
     -- , "node14", "node020"
     , "args"

tests/node/node026/Fix1795.idr

@@ -0,0 +1,6 @@
+import Data.String.Parser
+
+main : IO ()
+main = do
+    let res = parse (satisfy isDigit) "100"
+    printLn res

tests/node/node026/expected

@@ -0,0 +1,3 @@
+1/1: Building Fix1795 (Fix1795.idr)
+Main> Right ('1', 1)
+Main> Bye for now!

tests/node/node026/input

@@ -0,0 +1,2 @@
+:exec main
+:q

tests/node/node026/run

@@ -0,0 +1,4 @@
+rm -rf build
+
+$1 -p contrib --cg node --no-banner --no-color --console-width 0 Fix1795.idr < input
+