Merge pull request getodk#5 from clint-tseng/cxlt/fix-empty-constraints

fix two cases where "()" constraint/relevant would be produced

spec/src/convert-question-spec.ls

@@ -186,6 +186,14 @@ describe \constraint ->
     result = { type: \inputNumber, range: { min: 3, max: 9, maxInclusive: true } } |> convert-simple
     expect(result.constraint).toBe('(. > 3) and (. <= 9)')
 
+  test 'build number/date range constraint generation (min-only)' ->
+    result = { type: \inputNumber, range: { min: 3, minInclusive: true } } |> convert-simple
+    expect(result.constraint).toBe('(. >= 3)')
+
+  test 'build number/date range constraint generation (max)' ->
+    result = { type: \inputNumber, range: { max: 3, maxInclusive: true } } |> convert-simple
+    expect(result.constraint).toBe('(. <= 3)')
+
   test 'build number/date range false pruning' ->
     result = { type: \inputText, range: false } |> convert-simple
     expect(result.constraint).toBe(undefined)
@@ -254,6 +262,12 @@ describe 'followup question' ->
     expect(result.relevant).toBe("(selected(testquestion, 'testvalue'))")
     expect(context.successor-relevance).toBe(undefined)
 
+  test 'blank values are ignored' ->
+    context = new-context() with successor-relevance: ""
+    result = convert-question({ type: \inputText }, context)
+    expect(result.relevant).toBe(undefined)
+    expect(context.successor-relevance).toBe(undefined)
+
   test 'context is cleared at the end of group scope' ->
     context = new-context()
     convert-question({ type: \group, children: [{ type: \inputSelectOne, name: \test, other: [ \test ] }] }, context)

src/convert.ls

@@ -74,8 +74,12 @@ new-context = -> { seen-fields: {}, choices: {}, warnings: [] }
 
 # creates a range expression.
 gen-range = (range, self = \.) ->
-    [ "#self >#{if range.minInclusive is true then \= else ''} #{expr-value(range.min)}",
-      "#self <#{if range.maxInclusive is true then \= else ''} #{expr-value(range.max)}" ]
+  result = []
+  unless is-nonsense(range.min)
+    result.push("#self >#{if range.minInclusive is true then \= else ''} #{expr-value(range.min)}")
+  unless is-nonsense(range.max)
+    result.push("#self <#{if range.maxInclusive is true then \= else ''} #{expr-value(range.max)}")
+  result
 
 # returns an intermediate-formatted question clone (purely functional), but mutates context.
 convert-question = (question, context, prefix = []) ->
@@ -118,7 +122,8 @@ convert-question = (question, context, prefix = []) ->
 
   ## merge in convenience relevant logic definitions:
   if (successor-relevance = delete context.successor-relevance)?
-    question.relevant = (question.relevant ? []) ++ [ successor-relevance ] |> map(-> "(#it)") |> (.join(' and '))
+    unless is-nonsense(successor-relevance)
+      question.relevant = (question.relevant ? []) ++ [ successor-relevance ] |> map(-> "(#it)") |> (.join(' and '))
 
   ## drop successor information into context:
   if (other = delete question.other)?