fix autoApprovers panic (#25)

Fixes #24

Author: clstokes

Makefile

@@ -4,4 +4,4 @@ testdata:
 		-f testdata/input-parent.hujson \
 		-d testdata/departments/ \
 		-o testdata/output-file-to-compare-to.hujson \
-		-allow=acls,grants,groups,ipsets,ssh,tests
+		-allow=acls,autoApprovers,grants,groups,ipsets,ssh,tests

main.go

@@ -135,8 +135,11 @@ type SectionHandler func(sectionKey string, parentPath string, parent *jwcc.Obje
 
 func handleArray() SectionHandler {
 	return func(sectionKey string, parentPath string, parent *jwcc.Object, childPath string, childSection *jwcc.Member) {
+		if childSection == nil {
+			return
+		}
 		parentProps := parent.FindKey(ast.TextEqual(sectionKey))
-		if parentProps != nil {
+		if parentProps != nil && len(parentProps.Value.(*jwcc.Array).Values) > 0 {
 			pathComment(parentProps.Value.(*jwcc.Array).Values[0], parentPath)
 		}
 
@@ -160,6 +163,9 @@ func handleArray() SectionHandler {
 
 func handleObject() SectionHandler {
 	return func(sectionKey string, parentPath string, parent *jwcc.Object, childPath string, childSection *jwcc.Member) {
+		if childSection == nil {
+			return
+		}
 		parentProps := parent.FindKey(ast.TextEqual(sectionKey))
 		if parentProps != nil {
 			pathComment(parentProps.Value.(*jwcc.Object).Members[0], parentPath)
@@ -185,6 +191,9 @@ func handleObject() SectionHandler {
 func handleAutoApprovers() SectionHandler {
 	// https://tailscale.com/kb/1337/acl-syntax#auto-approvers-autoapprovers
 	return func(sectionKey string, parentPath string, parent *jwcc.Object, childPath string, childSection *jwcc.Member) {
+		if childSection == nil {
+			return
+		}
 		newObj := existingOrNewObject(*parent, sectionKey)
 
 		childSectionObj := childSection.Value.(*jwcc.Object)

testdata/departments/engineering/autoApprovers.hujson

@@ -0,0 +1,10 @@
+{
+    "autoApprovers": {
+        "routes": {
+            "10.0.0.0/32": [
+                "tag:example"
+            ]
+        },
+        "exitNode": ["tag:example"],
+    },
+}

testdata/departments/finance/autoApprovers.hujson

@@ -0,0 +1,9 @@
+{
+    "autoApprovers": {
+        "routes": {
+            "10.0.10.0/32": [
+                "tag:example"
+            ]
+        }
+    }
+}

testdata/output-file-to-compare-to.hujson

@@ -52,6 +52,21 @@
     },
   ],
 
+  "autoApprovers": {
+    "exitNode": [
+      // from `testdata/departments/engineering/autoApprovers.hujson`
+      "tag:example",
+    ],
+
+    "routes": {
+      // from `testdata/input-parent.hujson`
+      "10.0.0.0/32": ["tag:example"],
+
+      // from `testdata/departments/finance/autoApprovers.hujson`
+      "10.0.10.0/32": ["tag:example"],
+    },
+  },
+
   // from `testdata/input-parent.hujson`
   "extraDNSRecords": [
     {
@@ -87,7 +102,7 @@
     "ipset:parent": ["192.0.2.0"],
 
     // from `testdata/departments/finance/ipsets.hujson`
-    "ipset:parent": ["192.0.2.1"],
+    "ipset:finance": ["192.0.2.1"],
   },
 
   // from `testdata/input-parent.hujson`