Transform a file that has no beams section

examples/regression_jbeam/no-beams-repro.jbeam

@@ -0,0 +1,18 @@
+{
+"testpart":{
+    "nodes":[
+        ["id", "posX", "posY", "posZ"],
+        // Synthetic regression-test fixture, not vetted by the jbeam
+        // maintainer and not intended as a demo/example.
+        //
+        // Nodes and nothing else. A jbeam file is not obliged to have a beams
+        // section, and classifying, sorting and renaming need no beams at all.
+        // Only support classification does, and its answer here is simply that
+        // there are none.
+        ["nl0", 0.9,  -1.0, 0.1],
+        ["nl1", 0.9,  0.0,  0.1],
+        ["nr2", -0.9, -1.0, 0.1],
+        ["nr3", -0.9, 0.0,  0.1],
+    ],
+},
+}

src-extra/transformation/JbeamEdit/Transformation.hs

@@ -5,7 +5,7 @@
 import Data.Bool (bool)
 import Data.Foldable.Extra (notNull)
 import Data.Function (on)
 import Data.List (foldl', partition)
 import Data.List.NonEmpty (NonEmpty)
 import Data.List.NonEmpty qualified as NE
 import Data.Map (Map)
@@ -227,9 +227,9 @@
         Right movableVertices' ->
           let groupedVertices = M.fromListWith (++) movableVertices'
            in do
-                (badBeamNodes, conns) <-
-                  vertexConns (maxSupportCoordinates tfCfg) topNode groupedVertices
-                let (supportForest, nonSupportVertices) =
+                let (badBeamNodes, conns) =
+                      vertexConns (maxSupportCoordinates tfCfg) topNode groupedVertices
+                    (supportForest, nonSupportVertices) =
                       moveSupportVertices triangleVertexNames newNames tfCfg conns groupedVertices
                 newForest <-
                   foldM

src-extra/transformation/JbeamEdit/Transformation/BeamExtraction.hs

@@ -1,5 +1,7 @@
 module JbeamEdit.Transformation.BeamExtraction (vertexConns, possiblyBeam, extractBeams, extractBeamsWithMeta, beamInKnownSet) where
 
+import Data.Bool (bool)
+import Data.Either (fromRight)
 import Data.List (genericTake, sortOn)
 import Data.Map (Map)
 import Data.Map qualified as M
@@ -49,10 +51,11 @@ extractBeamFromArray sectionMeta vec
     maybeObject n@(Object _) = Just n
     maybeObject _ = Nothing
 
-extractBeams :: Node -> Either Text (Vector Node)
+extractBeams :: Node -> Vector Node
 extractBeams topNode =
-  NP.queryNodes beamQuery topNode
-    >>= NP.expectArray beamQuery
+  fromRight
+    V.empty
+    (NP.queryNodes beamQuery topNode >>= NP.expectArray beamQuery)
 
 extractBeamsWithMeta :: Vector Node -> ([Node], [Beam])
 extractBeamsWithMeta = go M.empty [] [] . V.toList
@@ -73,9 +76,8 @@ vertexConns
   :: Natural
   -> Node
   -> Map VertexTreeType [AnnotatedVertex]
-  -> Either Text ([Node], VertexConnMap)
-vertexConns maxSupport topNode vsPerType =
-  go <$> extractBeams topNode
+  -> ([Node], VertexConnMap)
+vertexConns maxSupport topNode vsPerType = go (extractBeams topNode)
   where
     knownNodeNames = S.fromList $ concatMap (map anVertexName) vsPerType
     go beamNodes =
@@ -103,7 +105,7 @@ vertexConns maxSupport topNode vsPerType =
               | (t, vs) <- M.toList topVerticesPerType
               , (v, c) <- vs
               ]
-       in (badNodes, vertexConnMap)
+       in bool (badNodes, vertexConnMap) (badNodes, M.empty) (null beamNodes)
 
 beamInKnownSet :: Set Text -> Beam -> Bool
 beamInKnownSet known (Beam (BeamPair a b) _) =

src-extra/transformation/JbeamEdit/Transformation/BeamValidation.hs

@@ -7,14 +7,13 @@
 ) where
 
 import Control.Monad (forM_, unless)
 import Data.List (foldl')
 import Data.List.NonEmpty (toList)
 import Data.Map qualified as M
 import Data.Set (Set)
 import Data.Set qualified as S
 import Data.Text (Text)
 import Data.Text qualified as T
-import Data.Vector qualified as V
 import JbeamEdit.Core.Node (Node)
 import JbeamEdit.IOUtils (humanJoin, putErrorStringLn, tryReadFile)
 import JbeamEdit.Parsing.Jbeam (parseNodes)
@@ -56,11 +55,7 @@
     Right (_, _, vf) -> Right (allVerticesInForest vf)
 
 extractFileBeams :: Node -> [Beam]
-extractFileBeams node =
-  case extractBeams node of
-    Right bs
-      | not (V.null bs) -> snd (extractBeamsWithMeta bs)
-    _ -> []
+extractFileBeams topNode = snd . extractBeamsWithMeta $ extractBeams topNode
 
 findInvalidRefs :: Set Text -> [Beam] -> [(Text, Text, Set Text)]
 findInvalidRefs allVertexNames beams =

test-extra/transformation/Spec.hs

@@ -162,6 +162,7 @@ main = hspec $ do
   letterEndingNodesSpec
   ySortingBandingSpec
   xColumnSortingSpec
+  noBeamsSpec
   metadataAcrossTreesSpec
   metadataPreservedSpec
   vertexTextSpec

test-extra/transformation/Spec/Helpers.hs

@@ -18,7 +18,11 @@ import Data.Text (Text)
 import Data.Text qualified as T
 import Data.Vector qualified as V
 import GHC.IsList (fromList)
-import JbeamEdit.Core.Node (Node (..), NumberValue (..), expectArray)
+import JbeamEdit.Core.Node (
+  Node (..),
+  NumberValue (..),
+  expectArray,
+ )
 import JbeamEdit.Core.NodePath qualified as NP
 import JbeamEdit.IOUtils (tryReadFile)
 import JbeamEdit.Parsing.Jbeam (parseNodes)

test-extra/transformation/Spec/Regression.hs

@@ -10,15 +10,30 @@ module Spec.Regression (
   metadataAcrossTreesSpec,
   metadataPreservedSpec,
   xColumnSortingSpec,
+  noBeamsSpec,
   vertexTextSpec,
 ) where
 
 import Data.List (sort)
+import Data.List.NonEmpty qualified as NE
 import Data.Map qualified as M
 import Data.Set qualified as S
+import Data.Text (Text)
 import Data.Text qualified as T
+import GHC.IsList (toList)
+import JbeamEdit.Core.Node (Node)
 import JbeamEdit.Transformation
+import JbeamEdit.Transformation.BeamExtraction (vertexConns)
 import JbeamEdit.Transformation.Config
+import JbeamEdit.Transformation.Types (
+  AnnotatedVertex (..),
+  VertexTree (..),
+ )
+import JbeamEdit.Transformation.VertexExtraction (
+  determineGroup',
+  getVertexForest,
+  verticesQuery,
+ )
 import Spec.Helpers
 import Test.Hspec
 
@@ -223,6 +238,52 @@ xColumnSortingSpec =
         Left err -> expectationFailure ("transform failed: " ++ T.unpack err)
         Right (_, _, _, resultNode) -> assert resultNode
 
+{- | A jbeam file is not obliged to have a beams section. Classifying, sorting
+and renaming need none: only support classification reads beams, and its
+answer without them is that there are no support nodes. Issue #229.
+
+`transform` instead fails the whole file, and the tool still exits 0, so a
+run over a directory leaves such files untouched without saying why.
+-}
+noBeamsFixture :: FilePath
+noBeamsFixture = "examples/regression_jbeam/no-beams-repro.jbeam"
+
+noBeamsSpec :: Spec
+noBeamsSpec =
+  describe "a file with no beams section" $ do
+    it "is transformed, keeping every node" $ do
+      topNode <- parseJbeamFile noBeamsFixture
+      case transform M.empty newTransformationConfig topNode of
+        Left err -> expectationFailure ("transform failed: " ++ T.unpack err)
+        Right (_, _, _, resultNode) ->
+          length (vertexCoordinates resultNode) `shouldBe` 4
+
+    it "counts a connection for every beamed vertex when there are beams" $ do
+      topNode <- parseJbeamFile supportRenameIdempotencyFixture
+      connectionCounts topNode
+        `shouldBe` Right [("nl0", 3), ("nl10", 3), ("nl20", 3)]
+
+    it "counts nothing at all when there are none" $ do
+      topNode <- parseJbeamFile noBeamsFixture
+      connectionCounts topNode `shouldBe` Right []
+
+{- | Grouping the vertices by tree type is what `transform` does before it
+asks for the counts, and is repeated here because the wrapper it uses is
+internal.
+-}
+connectionCounts :: Node -> Either Text [(Text, Int)]
+connectionCounts topNode = do
+  (_, _, forest) <- getVertexForest brks verticesQuery topNode
+  let annotated =
+        concatMap (concatMap (NE.toList . tAnnotatedVertices . snd) . toList) forest
+  grouped <- M.fromListWith (++) <$> mapM withGroup annotated
+  let (_, conns) =
+        vertexConns (maxSupportCoordinates newTransformationConfig) topNode grouped
+  pure (sort [(name, count) | (name, (_, count)) <- M.toList conns])
+  where
+    brks = xGroupBreakpoints newTransformationConfig
+    withGroup av = (,[av]) <$> determineGroup' brks (aVertex av)
+
 {- | The transformation reorders and renames, and never changes a coordinate,
 so a number has to come back out spelled the way the file wrote it. It used to
 be read as a value and written back from that value, which dropped the point