Set source for Grid prefixes in source maps

lib/hacks/grid-utils.js

@@ -604,7 +604,8 @@ function insertAreas(css, isDisabled) {
               Object.assign(i, {
                 raws: {
                   between: gridArea.raws.between
-                }
+                },
+                source: gridArea.source
               })
             )
           )
@@ -626,7 +627,8 @@ function insertAreas(css, isDisabled) {
               Object.assign(i, {
                 raws: {
                   between: gridArea.raws.between
-                }
+                },
+                source: gridArea.source
               })
             )
           )
@@ -661,7 +663,8 @@ function insertAreas(css, isDisabled) {
               Object.assign(i, {
                 raws: {
                   between: gridArea.raws.between
-                }
+                },
+                source: gridArea.source
               })
             )
           )
@@ -683,7 +686,8 @@ function insertAreas(css, isDisabled) {
               Object.assign(i, {
                 raws: {
                   between: gridArea.raws.between
-                }
+                },
+                source: gridArea.source
               })
             )
           )
@@ -732,7 +736,11 @@ function insertAreas(css, isDisabled) {
       .filter(p => p !== 'lastRule')
       .forEach(params => {
         if (data[params].length > 0 && lastRule) {
-          lastRule.after({ name: 'media', params })
+          lastRule.after({
+            name: 'media',
+            params,
+            source: data[params][0].source
+          })
           lastRule.next().append(data[params])
         }
       })
@@ -1164,8 +1172,12 @@ function autoplaceGridItems(decl, result, gap, autoflowValue = 'row') {
     node.selector = nodeSelector
 
     // insert prefixed row/column values
-    node.append({ prop: '-ms-grid-row', value: row.start })
+    node.append({ prop: '-ms-grid-row', source: decl.source, value: row.start })
-    node.append({ prop: '-ms-grid-column', value: column.start })
+    node.append({
+      prop: '-ms-grid-column',
+      source: decl.source,
+      value: column.start
+    })
 
     // insert rule
     parent.after(node)

test/autoprefixer.test.js

@@ -1337,6 +1337,20 @@ body > .two {
   equal(result.css, output)
 })
 
+test('sets source for grid nodes', () => {
+  for (let name of [
+    'grid-template-areas',
+    'grid-media-rules',
+    'grid-autoplacement'
+  ]) {
+    let result = postcss([prefixer('grid')]).process(read(name), {
+      from: name + '.css',
+      map: { inline: false }
+    })
+    equal(result.map.toJSON().sources, [name + '.css'])
+  }
+})
+
 test('ignores values for CSS3PIE props', () => {
   let css = read('pie')
   equal(postcss([compiler]).process(css).css, css)