Output function name with the first letter lowercase from camelCase

We introduced `toCamelCase` to use the same function name normalization
strategy as go-ethereum and support functions like `__beaconCallback`.

This change broke `ethereum` command. The subcommands for ethereum methods
were being prefixed by `-`. urfave/cli, the library we use for CLI
definition and parsing, does not fail if subcommands prefixed by - are used.
However, it does fail to recognize them; instead, it tries to recognize them
as flags, and flags with that name have not been defined.

`toCamelCase` used to uppercase the first letter. Later, in
`buildMethodInfo` where we create `dashedName` we were prefixing the
function name with `-` with uppercase-first letter.

The fix is easy, we need to ensure the first letter stays lowercase during
the normalization. Later, in `buildMethodInfo`, we specify explicitly where
do we want lowercase and uppercase with `uppercaseFirst` and `lowercaseFirst`.

Author: pdyraga

tools/generators/ethereum/contract_parsing.go

@@ -95,7 +95,7 @@ func buildContractInfo(
 	payableMethods := make(map[string]struct{})
 	for _, methodPayableInfo := range payableInfo {
 		if methodPayableInfo.Payable {
-			normalizedName := toCamelCase(methodPayableInfo.Name)
+			normalizedName := camelCase(methodPayableInfo.Name)
 			_, ok := payableMethods[normalizedName]
 			for idx := 0; ok; idx++ {
 				normalizedName = fmt.Sprintf("%s%d", normalizedName, idx)
@@ -138,7 +138,7 @@ func buildMethodInfo(
 	constMethods = make([]methodInfo, 0, len(methodsByName))
 
 	for name, method := range methodsByName {
-		normalizedName := toCamelCase(name)
+		normalizedName := camelCase(name)
 		dashedName := strings.ToLower(string(shortVarRegexp.ReplaceAll(
 			[]byte(normalizedName),
 			[]byte("-$0"),
@@ -278,24 +278,22 @@ func uppercaseFirst(str string) string {
 	if len(str) == 0 {
 		return str
 	}
-
 	return strings.ToUpper(str[0:1]) + str[1:]
 }
 
 func lowercaseFirst(str string) string {
 	if len(str) == 0 {
 		return str
 	}
-
 	return strings.ToLower(str[0:1]) + str[1:]
 }
 
-func toCamelCase(input string) string {
+func camelCase(input string) string {
 	parts := strings.Split(input, "_")
 	for i, s := range parts {
 		if len(s) > 0 {
 			parts[i] = strings.ToUpper(s[:1]) + s[1:]
 		}
 	}
-	return strings.Join(parts, "")
+	return lowercaseFirst(strings.Join(parts, ""))
 }

tools/generators/ethereum/contract_parsing_test.go

@@ -67,3 +67,44 @@ func TestUppercaseFirst(t *testing.T) {
 		})
 	}
 }
+
+func TestCamelCase(t *testing.T) {
+	var tests = map[string]struct {
+		input    string
+		expected string
+	}{
+		"empty string": {
+			input:    "",
+			expected: "",
+		},
+		"no underscores": {
+			input:    "HelloWorld",
+			expected: "helloWorld",
+		},
+		"with underscores": {
+			input:    "hello_world",
+			expected: "helloWorld",
+		},
+		"one underscore first": {
+			input:    "_beacon_callback",
+			expected: "beaconCallback",
+		},
+		"multiple underscores first": {
+			input:    "__beacon_callback",
+			expected: "beaconCallback",
+		},
+	}
+
+	for testName, test := range tests {
+		t.Run(testName, func(t *testing.T) {
+			actual := camelCase(test.input)
+			if actual != test.expected {
+				t.Errorf(
+					"unexpected output\nexpected: [%v]\nactual:   [%v]",
+					test.expected,
+					actual,
+				)
+			}
+		})
+	}
+}