diff --git a/selector/selector.go b/selector/selector.go
index abb2703..9c495e5 100644
--- a/selector/selector.go
+++ b/selector/selector.go
@@ -139,7 +139,7 @@ func validateUriExtension(uri string) error {
 }
 
 func bytesToJsonString(b []byte, abiSourceUri string) string {
-	var data any // TODO: zeuslawyer refactor to handle array or map. Eg of array https://raw.githubusercontent.com/Cyfrin/ccip-contracts/main/contracts-ccip/abi/v0.8/Router.json
+	var data any
 
 	if err := json.Unmarshal(b, &data); err != nil {
 		panic(fmt.Errorf("error parsing JSON from file at %s : %s", abiSourceUri, err))
@@ -148,7 +148,7 @@ func bytesToJsonString(b []byte, abiSourceUri string) string {
 	// Check if the data is a slice (array) or a map (object)
 	var abiData any
 	switch v := data.(type) {
-	case []interface{}:
+	case []any:
 		fmt.Println("Data is an array")
 		// You can work with v as a []interface{}
 		abiData = v
@@ -159,7 +159,7 @@ func bytesToJsonString(b []byte, abiSourceUri string) string {
 			panic(fmt.Errorf("Property 'abi' not found in unmarshalled JSON data. Check the file at %s", abiSourceUri))
 		}
 
-		// check that the abi property is an array
+		// check that the "abi" property is an array
 		_, ok = d.([]any)
 		if !ok {
 			fmt.Printf("Value of property 'abi' in supplied file is not an array")
diff --git a/selector/selector_test.go b/selector/selector_test.go
index 228fe97..f04a39b 100644
--- a/selector/selector_test.go
+++ b/selector/selector_test.go
@@ -1,6 +1,7 @@
 package selector
 
 import (
+	"fmt"
 	"path"
 	"strings"
 	"testing"
@@ -111,7 +112,7 @@ func TestFuncFromSelector(t *testing.T) {
 		{
 			name:     "file - object missing abi property",
 			selector: "0xa9059cbb",
-			path:     path.Join("testdata", "erc20.bad-abi.json"),
+			path:     path.Join("testdata", "bad-abi.json"),
 			panics:   true,
 			want:     "Property 'abi' not found",
 		},
@@ -129,6 +130,13 @@ func TestFuncFromSelector(t *testing.T) {
 			panics:   true,
 			want:     "invalid file/url extension",
 		},
+		{
+			name:     "URL - HTTP GET error",
+			selector: "0xa9059cbb",
+			url:      "https://fake.json",
+			panics:   true,
+			want:     fmt.Sprintf("Get \"%s\"", "https://fake.json"),
+		},
 		{
 			name:     "non existent selector",
 			selector: "0xa3063fba",
@@ -178,7 +186,63 @@ func TestFuncFromSelector(t *testing.T) {
 	}
 }
 
-// TODO @zeuslawyer do TestErrorFromSelector()
+func TestErrorSigFromSelector(t *testing.T) {
+	tests := []struct {
+		name     string
+		selector string
+		path     string
+		url      string
+		panics   bool
+		want     string // Hex string
+	}{
+		{
+			name:     "Happy Path - error with single param",
+			selector: "0xae236d9c",
+			path:     path.Join("testdata", "errors.abi.json"),
+			want:     "UnsupportedDestinationChain(uint64)",
+		},
+		{
+			name:     "Happy Path - error with no param",
+			selector: "0xd0d25976",
+			path:     path.Join("testdata", "errors.abi.json"),
+			want:     "SenderNotAllowed(address)",
+		},
+		{
+			name:     "Error Not In Abi - Should Panic",
+			selector: "0x1841b4e1",
+			path:     path.Join("testdata", "errors.abi.json"),
+			panics:   true,
+			want:     "no error with id",
+		},
+	}
+
+	for _, tc := range tests {
+		t.Run(tc.name, func(t *testing.T) {
+			if tc.panics {
+				defer func() {
+					if r := recover(); r != nil {
+						// Check if the panic value is as expected
+						errorString := r.(error).Error()
+						wantErrorSubString := tc.want
+						if strings.Contains(errorString, wantErrorSubString) == false {
+							t.Errorf("Expected panic message to contain: %s, got: %v", wantErrorSubString, errorString)
+						}
+					} else {
+						// The function did not panic as expected
+						t.Error("Expected the function to panic, but it did not")
+					}
+				}()
+
+				ErrorSigFromSelector(tc.selector, tc.path, tc.url)
+			} else {
+				got := ErrorSigFromSelector(tc.selector, tc.path, tc.url)
+				if got != tc.want {
+					t.Errorf("ErrorSigFromSelector(%s) = %s, want %s", tc.selector, got, tc.want)
+				}
+			}
+		})
+	}
+}
 
 func TestEventFromTopicHash(t *testing.T) {
 	tests := []struct {
@@ -190,7 +254,7 @@ func TestEventFromTopicHash(t *testing.T) {
 		want      string // Hex string
 	}{
 		// TODO @zeuslawyer do remaining test cases
-		// TODO should can the abi decoding function be reused to decode topic hash?
+		// TODO  can the abiDecode() function be reused to decode topic hash?
 		{
 			name:      "Event Signature from ABI file",
 			topicHash: "0x8c5be1e5ebec7d5bd14f71427d1e84f3dd0314c0f7b2291e5b200ac8c7c3b925", // "0x8c5be1e5",
diff --git a/selector/testdata/erc20.bad-abi.json b/selector/testdata/bad-abi.json
similarity index 100%
rename from selector/testdata/erc20.bad-abi.json
rename to selector/testdata/bad-abi.json
diff --git a/selector/testdata/errors.abi.json b/selector/testdata/errors.abi.json
new file mode 100644
index 0000000..6faa067
--- /dev/null
+++ b/selector/testdata/errors.abi.json
@@ -0,0 +1,29 @@
+[
+  {
+    "inputs": [],
+    "name": "InsufficientFeeTokenAmount",
+    "type": "error"
+  },
+  {
+    "inputs": [
+      {
+        "internalType": "uint64",
+        "name": "destChainSelector",
+        "type": "uint64"
+      }
+    ],
+    "name": "UnsupportedDestinationChain",
+    "type": "error"
+  },
+  {
+    "inputs": [
+      {
+        "internalType": "address",
+        "name": "sender",
+        "type": "address"
+      }
+    ],
+    "name": "SenderNotAllowed",
+    "type": "error"
+  }
+]