feat: add gas limit option to raw transactor (#311)

This pull request introduces support for specifying a gas limit when
generating a raw signer in the Chainlink deployments framework. The
changes add a flexible options pattern to the signer generator, allowing
users to set a custom gas limit if needed. Unit tests have been updated
to cover this new functionality.

**New feature: Gas limit support for raw signer generator**
- Added a `GeneratorOptions` struct and options pattern
(`GeneratorOption`, `WithGasLimit`) to `signer_generator.go`, enabling
configuration of gas limit for raw signers.
- Updated `TransactorFromRaw` to accept options and set the gas limit on
the generated transactor if provided.
[[1]](diffhunk://#diff-d969a93d4b9bf394c24013f13cd08f330806edf95bd4536a0e3b78935e38c636R27-R60)
[[2]](diffhunk://#diff-d969a93d4b9bf394c24013f13cd08f330806edf95bd4536a0e3b78935e38c636R74-R76)

**Testing improvements**
- Enhanced unit tests in `signer_generator_test.go` to verify correct
gas limit behavior, including cases with and without custom gas limits.
[[1]](diffhunk://#diff-1212d4f28859805b9036ae27dd95525343ab0ec9143d856d84980583985476b2L33-R51)
[[2]](diffhunk://#diff-1212d4f28859805b9036ae27dd95525343ab0ec9143d856d84980583985476b2L60-R82)

**Documentation**
- Added a changeset documenting the new gas limit option for the raw
signer generator.

Author: ecPablo

.changeset/young-colts-chew.md

@@ -0,0 +1,5 @@
+---
+"chainlink-deployments-framework": minor
+---
+
+Add support for gas limit option on raw signer generator

chain/evm/provider/signer_generator.go

@@ -24,16 +24,41 @@ var (
 	_ SignerGenerator = (*transactorFromKMSSigner)(nil)
 )
 
+// GeneratorOptions contains configuration options for the SignerGenerator.
+type GeneratorOptions struct {
+	gasLimit uint64
+}
+
+// GeneratorOption is a function that modifies GeneratorOptions.
+type GeneratorOption func(*GeneratorOptions)
+
+func WithGasLimit(gasLimit uint64) GeneratorOption {
+	return func(opts *GeneratorOptions) {
+		opts.gasLimit = gasLimit
+	}
+}
+
 // TransactorFromRaw returns a generator which creates a transactor from a raw private key.
-func TransactorFromRaw(privKey string) SignerGenerator {
+func TransactorFromRaw(privKey string, opts ...GeneratorOption) SignerGenerator {
+	// load default options
+	defaultOpts := &GeneratorOptions{
+		gasLimit: 0,
+	}
+	// apply provided options
+	for _, opt := range opts {
+		opt(defaultOpts)
+	}
+
 	return &transactorFromRaw{
-		privKey: privKey,
+		privKey:  privKey,
+		gasLimit: defaultOpts.gasLimit,
 	}
 }
 
 // transactorFromRaw is a SignerGenerator that creates a transactor from a private key.
 type transactorFromRaw struct {
-	privKey string
+	privKey  string
+	gasLimit uint64
 }
 
 // Generate parses the hex encoded private key and returns the bind transactor options.
@@ -47,6 +72,9 @@ func (g *transactorFromRaw) Generate(chainID *big.Int) (*bind.TransactOpts, erro
 	if err != nil {
 		return nil, err
 	}
+	if g.gasLimit > 0 {
+		transactor.GasLimit = g.gasLimit
+	}
 
 	return transactor, nil
 }

chain/evm/provider/signer_generator_test.go

@@ -30,14 +30,25 @@ func Test_TransactorFromRaw(t *testing.T) {
 		name        string
 		givePrivKey string
 		giveChainID *big.Int
-		want        string
+		giveOpts    []GeneratorOption
+		wantAddr    string
+		wantGas     uint64
 		wantErr     string
 	}{
 		{
-			name:        "valid default account and private key",
+			name:        "valid default account and private key (no gas limit)",
 			givePrivKey: hexPrivKey,
 			giveChainID: testChainIDBig,
-			want:        privKeyHex,
+			wantAddr:    privKeyHex,
+			wantGas:     0,
+		},
+		{
+			name:        "valid with custom gas limit",
+			givePrivKey: hexPrivKey,
+			giveChainID: testChainIDBig,
+			giveOpts:    []GeneratorOption{WithGasLimit(123456)},
+			wantAddr:    privKeyHex,
+			wantGas:     123456,
 		},
 		{
 			name:        "invalid private key",
@@ -57,16 +68,19 @@ func Test_TransactorFromRaw(t *testing.T) {
 		t.Run(tt.name, func(t *testing.T) {
 			t.Parallel()
 
-			gen := TransactorFromRaw(tt.givePrivKey)
+			gen := TransactorFromRaw(tt.givePrivKey, tt.giveOpts...)
 
 			got, err := gen.Generate(tt.giveChainID)
 			if tt.wantErr != "" {
 				require.Error(t, err)
 				require.ErrorContains(t, err, tt.wantErr)
-			} else {
-				require.NoError(t, err)
-				assert.Equal(t, tt.want, got.From.Hex())
+
+				return
 			}
+
+			require.NoError(t, err)
+			assert.Equal(t, tt.wantAddr, got.From.Hex())
+			assert.Equal(t, tt.wantGas, got.GasLimit)
 		})
 	}
 }