Merge pull request #497 from reubenmiller/fix-jsonnet-template-helpers-get-has

fix(jsonnet): check if value is an object before accessing nested properties

Author: reubenmiller

pkg/mapbuilder/mapbuilder.go

@@ -500,7 +500,9 @@ func evaluateJsonnet(imports string, snippets ...string) (string, error) {
 				},
 		Get(o, f, default=null)::
 			local get_(o, ks) =
-				if ! std.objectHas(o, ks[0]) then
+				if std.type(o) != 'object' then
+					default
+				else if ! std.objectHas(o, ks[0]) then
 					default
 				else if std.length(ks) == 1 then
 					o[ks[0]]
@@ -509,7 +511,9 @@ func evaluateJsonnet(imports string, snippets ...string) (string, error) {
 				get_(o, std.split(f, '.')),
 		Has(o, f)::
 			local has_(o, ks) =
-				if ! std.objectHas(o, ks[0]) then
+				if std.type(o) != 'object' then
+					false
+				else if ! std.objectHas(o, ks[0]) then
 					false
 				else if std.length(ks) == 1 then
 					true

tests/manual/template/template_get.yml

@@ -41,3 +41,50 @@ tests:
             "dummy": 2
           }
         }
+
+  It safely access input if when there is no piped input:
+    command: |
+        c8y template execute --template "_.Get(input.value, 'nestedProp2', {dummy: 2})" -c=false -o json
+    stdout:
+      exactly: |
+        {
+          "dummy": 2
+        }
+
+  It safely access nested properties of input if when there is no piped input:
+    command: |
+        c8y template execute --template "_.Get(input, 'value.nestedProp2', {dummy: 2})" -c=false -o json
+    stdout:
+      exactly: |
+        {
+          "dummy": 2
+        }
+
+  It safely access nested properties of input if when there is piped input:
+    command: |
+        c8y template execute --template "{nestedProp2: 1}" \
+        | c8y template execute --template "{output: _.Get(input, 'value.nestedProp2', {dummy: 2})}" -c=false -o json
+    stdout:
+      exactly: |
+        {
+          "output": 1
+        }
+  
+  It safely checks for nested properties when there is piped input:
+    command: |
+        c8y template execute --template "{nestedProp2: 1}" \
+        | c8y template execute --template "{output: _.Has(input, 'value.nestedProp2')}" -c=false -o json
+    stdout:
+      exactly: |
+        {
+          "output": true
+        }
+
+  It safely checks for nested properties when there is no piped input:
+    command: |
+        c8y template execute --template "{output: _.Has(input, 'value.nestedProp2')}" -c=false -o json
+    stdout:
+      exactly: |
+        {
+          "output": false
+        }