A fully evaluated may still have children nodes

haskell-debugger/GHC/Debugger/Stopped/Variables.hs

@@ -131,9 +131,7 @@ termToVarInfo key term0 = do
   -- We only want to return @SpecificVariable@ (which allows expansion) for
   -- values with sub-fields or thunks.
   varRef <- do
-    if GHCI.isFullyEvaluatedTerm term ||
-       -- Even if it is already evaluated, we do want to display a
-       -- structure as long if it is not a "boring type" (one that does not
+    if -- Display a structure as long it is not a "boring type" (one that does not
        -- provide useful information from being expanded)
        -- (e.g. consider how awkward it is to expand Char# 10 and I# 20)
        (not isThunk && (isBoringTy ty || not (hasDirectSubTerms term)))

test/integration-tests/data/T110/T110.hs

@@ -0,0 +1,11 @@
+module Main where
+
+data T = T !Int !Int
+  deriving Show
+
+main = do
+  y (T 333 34)
+
+y :: T -> IO ()
+y t = do
+  print t

test/integration-tests/test/adapter.test.ts

@@ -604,6 +604,28 @@ describe("Debug Adapter Tests", function () {
             const m2 = await getMutVarValue()
             assert.strictEqual(m2.value, "True")
         })
+
+        it('inspect fully evaluated type (issue #110)', async () => {
+            let config = mkConfig({
+                  projectRoot: "/data/T110",
+                  entryFile: "T110.hs",
+                  entryPoint: "main",
+                  entryArgs: [],
+                  extraGhcArgs: []
+                })
+
+            const expected = { path: config.projectRoot + "/" + config.entryFile, line: 11 }
+            await dc.hitBreakpoint(config, { path: config.entryFile, line: 11 }, expected, expected);
+
+            let locals = await fetchLocalVars();
+            const tVar = await forceLazy(locals.get('t'));
+            assert.strictEqual(tVar.value, "T")
+            const tChild = await expandVar(tVar); // No force needed, is fully evaluated and can expand
+            const _1Var = await tChild.get('_1');
+            const _2Var = await tChild.get('_2');
+            assert.strictEqual(_1Var.value, '333');
+            assert.strictEqual(_2Var.value, '34');
+        })
     })
     describe("Stepping out (step-out)", function () {