fixed presenting keyword values in JSON style

Author: flyx

test/tpresenter.nim

@@ -169,3 +169,11 @@ suite "Presenter":
       startMapEvent(), scalarEvent("foo"), scalarEvent("bar"), scalarEvent("baz"),
       startSeqEvent(), endSeqEvent(), endMapEvent())
     assertOutput(input, "{\n  \"foo\": \"bar\",\n  \"baz\": []\n}\n", jsonOptions)
+
+  test "JSON output with keyword values":
+    var input = inputSingle(scalarEvent("true"))
+    assertOutput(input, "true\n", jsonOptions)
+    input = inputSingle(scalarEvent("false", yTagBoolean))
+    assertOutput(input, "false\n", jsonOptions)
+    input = inputSingle(scalarEvent("~", yTagNull))
+    assertOutput(input, "null\n", jsonOptions)

yaml/presenter.nim

@@ -718,7 +718,8 @@ proc doPresent(
         ctx.safeWrite("...")
         ctx.safeNewline()
       ctx.wroteDirectivesEnd =
-        item.explicitDirectivesEnd or ctx.options.directivesEnd == deAlways or not s.peek().emptyProperties()
+        item.explicitDirectivesEnd or ctx.options.directivesEnd == deAlways or (
+        ctx.options.directivesEnd != deNever and not s.peek().emptyProperties())
 
       if ctx.options.directivesEnd != deNever:
         resetHandles(ctx.handles)
@@ -804,7 +805,7 @@ proc doPresent(
       case ctx.options.quoting
       of sqJson:
         var hint = yTypeUnknown
-        if ctx.levels.len > 0 and ctx.state == dFlowMapValue: hint = guessType(item.scalarContent)
+        if ctx.levels.len == 0 or ctx.state == dFlowMapValue: hint = guessType(item.scalarContent)
         let tag = item.scalarProperties.tag
         if tag in [yTagQuestionMark, yTagBoolean] and
             hint in {yTypeBoolTrue, yTypeBoolFalse}: