feat(lib): Move terms function to proper place

This 'view' was not really a view, because it did not produce results
based on the variable store. Instead it simply took parameters and
returned an object that was a valid terms query.

This is a good feature to have, but it should be internal to this
library only.

test/lib/leaf/terms.js

@@ -0,0 +1,41 @@
+const terms = require('../../../lib/leaf/terms');
+
+module.exports.tests = {};
+
+module.exports.tests.terms = function(test, common) {
+  test('null returned if property missing', function(t) {
+    const query = terms();
+
+    t.equal(null, query, 'null query returned');
+    t.end();
+  });
+
+  test('null returned if value missing', function(t) {
+    const query = terms('theproperty');
+
+    t.equal(null, query, 'null query returned');
+    t.end();
+  });
+
+  test('terms query returned with property and value', function(t) {
+    const query = terms('theproperty', 'thevalue');
+
+    const expected = {
+      terms: {
+        theproperty: 'thevalue'
+      }
+    };
+
+    t.deepEqual(query, expected, 'valid terms query');
+    t.end();
+  });
+};
+
+module.exports.all = function (tape, common) {
+  function test(name, testFunction) {
+    return tape('lib/leaf/terms ' + name, testFunction);
+  }
+  for( var testCase in module.exports.tests ){
+    module.exports.tests[testCase](test, common);
+  }
+};

test/run.js

@@ -8,6 +8,7 @@ var tests = [
   require('./layout/FilteredBooleanQuery.js'),
   require('./layout/StructuredFallbackQuery.js'),
   require('./layout/VenuesQuery.js'),
+  require('./lib/leaf/terms.js'),
   require('./lib/Variable.js'),
   require('./lib/VariableStore.js'),
   require('./view/address.js'),

view/layers.js

@@ -1,4 +1,4 @@
-var terms = require('./terms');
+const terms = require('../lib/leaf/terms');
 
 module.exports = function( vs ){
   if( !vs.isset('layers')) {

view/sources.js

@@ -1,4 +1,4 @@
-var terms = require('./terms');
+const terms = require('../lib/leaf/terms');
 
 module.exports = function( vs ){
   if( !vs.isset('sources')) {