Fix PatchJSON error when no component params are defined.

* PatchJSON guards against missing 'components' key.
* BuildEnvParamsForModule / params_for_module.libsonnet returns empty components key when no component params are found.

Closes #789
Signed-off-by: Oren Shomron <shomron@gmail.com>

pkg/params/for_test.go

@@ -54,6 +54,13 @@ func TestBuildEnvParamsForModule(t *testing.T) {
 			moduleName:      "no-match",
 			output:          "no_match.jsonnet",
 		},
+		{
+			name:            "empty input, still output components field",
+			input:           "input_empty.jsonnet",
+			componentParams: "component_empty.jsonnet",
+			moduleName:      "no-match",
+			output:          "no_match.jsonnet",
+		},
 	}
 
 	for _, tc := range cases {

pkg/params/patch_json.go

@@ -29,8 +29,8 @@ func PatchJSON(jsonObject, patch, patchName string) (string, error) {
 
 var snippetMergeComponentPatch = `
 function(target, patch, patchName)
-	if std.objectHas(patch.components, patchName) then
-		std.mergePatch(target, patch.components[patchName])
-	else
-		target
+  if std.objectHas(patch, 'components') && std.objectHas(patch.components, patchName) then
+    std.mergePatch(target, patch.components[patchName])
+  else
+    target
 `

pkg/params/patch_json_test.go

@@ -36,3 +36,16 @@ func Test_PatchJSON(t *testing.T) {
 
 	test.AssertOutput(t, "rbac-1-patched.json", got)
 }
+
+func Test_PatchJSON_EmptyPatch(t *testing.T) {
+	jsonObject, err := ioutil.ReadFile(filepath.Join("testdata", "rbac-1.json"))
+	require.NoError(t, err)
+
+	patch, err := ioutil.ReadFile(filepath.Join("testdata", "patch-empty.json"))
+	require.NoError(t, err)
+
+	got, err := PatchJSON(string(jsonObject), string(patch), "rbac-1")
+	require.NoError(t, err)
+
+	test.AssertOutput(t, "rbac-1.json", got)
+}

pkg/params/rice-box.go

@@ -25,19 +25,19 @@ func init() {
 	// define files
 	file2 := &embedded.EmbeddedFile{
 		Filename:    "modularize_params.libsonnet",
-		FileModTime: time.Unix(1530832602, 0),
+		FileModTime: time.Unix(1531169022, 0),
 		Content:     string("function(moduleName, params)\n    local prefix = if (moduleName == \"/\" || moduleName == \"\") then \"\" else \"%s.\" % moduleName;\n\n    local baseObject = if std.objectHas(params, \"global\")\n        then {global: params.global}\n        else {};\n\n    baseObject + {\n        components: {\n            [\"%s%s\" % [prefix, key]]: params.components[key]\n            for key in std.objectFieldsAll(params.components)\n        },\n    }"),
 	}
 	file3 := &embedded.EmbeddedFile{
 		Filename:    "params_for_module.libsonnet",
-		FileModTime: time.Unix(1530891505, 0),
-		Content:     string("function(moduleName, input)\n   local isModule(key) = std.length(std.split(key, \".\")) > 1;\n\n   local localizeKey(key) =\n      if isModule(key)\n      then\n         local parts = std.split(key, \".\");\n         parts[std.length(parts)-1]\n      else key;\n\n   local findInRoot(key, value) =\n      if isModule(key)\n      then {[key]:null}\n      else {[key]:value};\n\n   local findInModule(moduleName, key, value) =\n      if std.startsWith(key, moduleName)\n      then {[localizeKey(key)]: value}\n      else {[localizeKey(key)]: null};\n\n   local findValue(moduleName, key, value) =\n      if moduleName == \"/\"\n      then findInRoot(key, value)\n      else findInModule(moduleName, key, value);\n\n   local fn(moduleName, params) = [\n      findValue(moduleName, key, params.components[key])\n      for key in std.objectFields(params.components)\n   ];\n\n   local foldFn(aggregate, object) =\n      local o = {\n         components+: {\n            [x]:+ object[x]\n            for x in std.objectFields(object)\n            if object[x] != null\n         },\n      };\n\n      aggregate + o;\n\n   local a = fn(moduleName, input);\n\n   std.foldl(foldFn, a, {})\n\n"),
+		FileModTime: time.Unix(1532616716, 0),
+		Content:     string("function(moduleName, input)\n   local isModule(key) = std.length(std.split(key, \".\")) > 1;\n\n   local localizeKey(key) =\n      if isModule(key)\n      then\n         local parts = std.split(key, \".\");\n         parts[std.length(parts)-1]\n      else key;\n\n   local findInRoot(key, value) =\n      if isModule(key)\n      then {[key]:null}\n      else {[key]:value};\n\n   local findInModule(moduleName, key, value) =\n      if std.startsWith(key, moduleName)\n      then {[localizeKey(key)]: value}\n      else {[localizeKey(key)]: null};\n\n   local findValue(moduleName, key, value) =\n      if moduleName == \"/\"\n      then findInRoot(key, value)\n      else findInModule(moduleName, key, value);\n\n   local fn(moduleName, params) = [\n      findValue(moduleName, key, params.components[key])\n      for key in std.objectFields(params.components)\n   ];\n\n   local foldFn(aggregate, object) =\n      local o = {\n         components+: {\n            [x]:+ object[x]\n            for x in std.objectFields(object)\n            if object[x] != null\n         },\n      };\n\n      aggregate + o;\n\n   local a = fn(moduleName, input);\n\n   local init = {components: {}};\n\n   std.foldl(foldFn, a, init)\n\n"),
 	}
 
 	// define dirs
 	dir1 := &embedded.EmbeddedDir{
 		Filename:   "",
-		DirModTime: time.Unix(1530832602, 0),
+		DirModTime: time.Unix(1531169022, 0),
 		ChildFiles: []*embedded.EmbeddedFile{
 			file2, // "modularize_params.libsonnet"
 			file3, // "params_for_module.libsonnet"
@@ -51,7 +51,7 @@ func init() {
 	// register embeddedBox
 	embedded.RegisterEmbeddedBox(`scripts`, &embedded.EmbeddedBox{
 		Name: `scripts`,
-		Time: time.Unix(1530832602, 0),
+		Time: time.Unix(1531169022, 0),
 		Dirs: map[string]*embedded.EmbeddedDir{
 			"": dir1,
 		},

pkg/params/scripts/params_for_module.libsonnet

@@ -41,5 +41,7 @@ function(moduleName, input)
 
    local a = fn(moduleName, input);
 
-   std.foldl(foldFn, a, {})
+   local init = {components: {}};
+
+   std.foldl(foldFn, a, init)
 

pkg/params/testdata/build_env_params/component_empty.jsonnet

+{
+  global: {
+  },
+  // Component-level parameters, defined initially from 'ks prototype use ...'
+  // Each object below should correspond to a component in the components/ directory
+  components: {
+  },
+}

pkg/params/testdata/build_env_params/input_empty.jsonnet

+{
+    components: {},
+}
\ No newline at end of file

pkg/params/testdata/patch-empty.json

+{}
\ No newline at end of file

pkg/params/testdata/rbac-1.json

 {
-    "apiVersion": "rbac.authorization.k8s.io/v1beta1",
-    "kind": "ClusterRoleBinding",
-    "metadata": {
-        "name": "cert-manager",
-        "labels": {
-            "app": "cert-manager",
-            "chart": "cert-manager-0.2.2",
-            "release": "cert-manager",
-            "heritage": "Tiller"
-        }
-    },
-    "roleRef": {
-        "apiGroup": "rbac.authorization.k8s.io",
-        "kind": "ClusterRole",
-        "name": "cert-manager"
-    },
-    "subjects": [{
-        "name": "cert-manager",
-        "namespace": "default",
-        "kind": "ServiceAccount"
-    }]
-}
\ No newline at end of file
+   "apiVersion": "rbac.authorization.k8s.io/v1beta1",
+   "kind": "ClusterRoleBinding",
+   "metadata": {
+      "labels": {
+         "app": "cert-manager",
+         "chart": "cert-manager-0.2.2",
+         "heritage": "Tiller",
+         "release": "cert-manager"
+      },
+      "name": "cert-manager"
+   },
+   "roleRef": {
+      "apiGroup": "rbac.authorization.k8s.io",
+      "kind": "ClusterRole",
+      "name": "cert-manager"
+   },
+   "subjects": [
+      {
+         "kind": "ServiceAccount",
+         "name": "cert-manager",
+         "namespace": "default"
+      }
+   ]
+}