Newbie question trying to verify merle tree for a depth of 0 and 1

Question

Following code seems to work for depth = 0 but fails for both depth = 0 and depth = 1.

template Spend(depth) {
    signal input digest;
    signal input nullifier;
    signal private input nonce;
    signal private input sibling[depth];
    signal private input direction[depth];   
    signal spend_coin_path_hash[depth]; // array of hash values for spend coin merkle path
    //signal spend_coin_hash[depth];
    //signal spend_coin_path_digest; // variable to store the calculated merkle digest
    var i; // variable i to track tree depth

    // TODO
    if (depth=0) {
        component comp_spend_coin_hash = Mimc2();
        comp_spend_coin_hash.in0 <== nullifier;
        comp_spend_coin_hash.in1 <== nonce;
        spend_coin_path_hash[0] <== comp_spend_coin_hash.out; //set the initial hash of leaf for the spend coin

        // constraint to match on digest
        spend_coin_path_hash[0] === digest;
    }
    if (depth=1) {
        component comp2_spend_coin_hash = Mimc2();
        component comp3 = SelectiveSwitch();
        comp2_spend_coin_hash.in0 <== nullifier;
        comp2_spend_coin_hash.in1 <== nonce;
        spend_coin_path_hash[0] <== comp_spend_coin_hash.out; 
        comp3.in0 <== spend_coin_path_hash[0];
        comp3.in1 <== sibling[0];
        comp3.s <== direction[0];
        comp_spend_coin_hash[depth].in0 <== comp3.out0;
        comp_spend_coin_hash[depth].in1 <== comp3.out1;
        spend_coin_path_hash[depth] <== comp_spend_coin_hash[depth].out;   
        
        // constraint to match on digest
        spend_coin_path_hash[depth] === digest;
    }
}

Get the error message Error: Invalid signal identifier: main.comp2_spend_coin_hash.in0