Merge pull request thomas4019#8 from jeniawhite/evgb-IncMulMinMaxOperators

Patching numeric operators in edge cases

Author: thomas4019

test/update.js

@@ -38,18 +38,18 @@ describe('update: ', function() {
     })
 
     it('$inc', function() {
-      assert.equal(convertUpdate('data', { $inc: { count: 2 } }), 'jsonb_set(data,\'{count}\',to_jsonb(Cast(data->>\'count\' as numeric)+2))')
+      assert.equal(convertUpdate('data', { $inc: { count: 2 } }), 'jsonb_set(data,\'{count}\',to_jsonb(COALESCE(Cast(data->>\'count\' as numeric),0)+2))')
     })
     it('$mul', function() {
-      assert.equal(convertUpdate('data', { $mul: { count: 2 } }), 'jsonb_set(data,\'{count}\',to_jsonb(Cast(data->>\'count\' as numeric)*2))')
+      assert.equal(convertUpdate('data', { $mul: { count: 2 } }), 'jsonb_set(data,\'{count}\',to_jsonb(COALESCE(Cast(data->>\'count\' as numeric),0)*2),TRUE)')
     })
 
 
     it('$min', function() {
-      assert.equal(convertUpdate('data', { $min: { count: 5 } }), 'jsonb_set(data,\'{count}\',to_jsonb(LEAST(Cast(data->>\'count\' as numeric),5)))')
+      assert.equal(convertUpdate('data', { $min: { count: 5 } }), 'jsonb_set(data,\'{count}\',to_jsonb(LEAST(COALESCE(Cast(data->>\'count\' as numeric),0),5)))')
     })
     it('$max', function() {
-      assert.equal(convertUpdate('data', { $max: { count: 5 } }), 'jsonb_set(data,\'{count}\',to_jsonb(GREATEST(Cast(data->>\'count\' as numeric),5)))')
+      assert.equal(convertUpdate('data', { $max: { count: 5 } }), 'jsonb_set(data,\'{count}\',to_jsonb(GREATEST(COALESCE(Cast(data->>\'count\' as numeric),0),5)))')
     })
 
     it('$rename', function() {
@@ -67,6 +67,11 @@ describe('update: ', function() {
   })
 
   describe('combined operators', function() {
-    assert.equal(convertUpdate('data', { $set: { active: true }, $inc: { purchases: 2 } }), 'jsonb_set(jsonb_set(data,\'{active}\',\'true\'::jsonb),\'{purchases}\',to_jsonb(Cast(data->>\'purchases\' as numeric)+2))')
+    it('$set,$inc', function() {
+      assert.equal(convertUpdate('data', { $set: { active: true }, $inc: { purchases: 2 } }), 'jsonb_set(jsonb_set(data,\'{active}\',\'true\'::jsonb),\'{purchases}\',to_jsonb(COALESCE(Cast(data->>\'purchases\' as numeric),0)+2))')
+    })
+    it('$set,$unset,$inc', function() {
+      assert.equal(convertUpdate('data', { $set: { active: true }, $unset: { field: 'value' }, $inc: { purchases: 2 } }), 'jsonb_set(jsonb_set(data,\'{active}\',\'true\'::jsonb) #- \'{field}\',\'{purchases}\',to_jsonb(COALESCE(Cast(data->>\'purchases\' as numeric),0)+2))')
+    })
   })
 })

update.js

@@ -32,12 +32,16 @@ function convertOp(input, op, data, fieldName, upsert) {
     case '$unset':
       return input + ' #- ' + pgPath
     case '$inc':
+      // TODO: Handle null value keys (MongoDB drops the operation with "Cannot apply $inc to a value of non-numeric type null")
       return 'jsonb_set(' + input + ',' + pgPath + ',to_jsonb(' + prevNumericVal + '+' + value + '))'
     case '$mul':
-      return 'jsonb_set(' + input + ',' + pgPath + ',to_jsonb(' + prevNumericVal + '*' + value + '))'
+      // TODO: Handle null value keys (MongoDB drops the operation with "Cannot apply $mul to a value of non-numeric type null")
+      return 'jsonb_set(' + input + ',' + pgPath + ',to_jsonb(' + prevNumericVal + '*' + value + '),TRUE)'
     case '$min':
+      // TODO: $min between existing key with value null with anything will output null
       return 'jsonb_set(' + input + ',' + pgPath + ',to_jsonb(LEAST(' + prevNumericVal + ',' + value + ')))'
     case '$max':
+      // TODO: $max between existing key with value null with anything will output value
       return 'jsonb_set(' + input + ',' + pgPath + ',to_jsonb(GREATEST(' + prevNumericVal + ',' + value + ')))'
     case '$rename':
       const pgNewPath = util.toPostgresPath(value.split('.'))

util.js

@@ -46,7 +46,7 @@ exports.toPostgresPath = function(path) {
 }
 
 exports.toNumeric = function(path) {
-  return 'Cast(' + path + ' as numeric)'
+  return 'COALESCE(Cast(' + path + ' as numeric),0)'
 }
 
 const typeMapping = {