automatic gas estimation

src/seth/CHANGELOG.md

@@ -15,6 +15,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - `seth index` command returns the slot number for the specified mapping type and input data
 - `seth --from-fix` command converts fixed point numbers into parsed integers with the specified number of decimals
 - `seth run-tx` now fetches contract source from etherscan if `ETHERSCAN_API_KEY` is set
+- `seth mktx` now estimates gas limit eth `ETH_GAS` is not set
 
 ### Fixed
 

src/seth/README.md

@@ -238,7 +238,7 @@ wei—the smallest possible amount of ether—to the [Ethereum
 Foundation's donation address]:
 
     $ seth send --value 1 0xfB6916095ca1df60bB79Ce92cE3Ea74c37c5d359
-    seth-send: warning: `ETH_GAS' not set; using default gas amount
+    seth-send: warning: `ETH_GAS' not set; using estimated gas amount
     Ethereum account passphrase (not echoed):
     seth-send: Published transaction with 0 bytes of calldata.
     seth-send: 0xe428d4bb148ded426777ae892578507e4f394f608ad9d3a9d0229e8348ba72e3
@@ -829,7 +829,7 @@ Sign and publish a transaction to the blockchain.
 | ------------- | --------------- | ------------ | ---------------                   |
 | `--block`     | `ETH_BLOCK`     | `latest`     | block number                      |
 | `--from`      | `ETH_FROM`      | n/a          | sender                            |
-| `--gas`       | `ETH_GAS`       | `200000`     | gas quantity                      |
+| `--gas`       | `ETH_GAS`       | estimated    | gas quantity                      |
 | `--gas-price` | `ETH_GAS_PRICE` |              | gas price                         |
 | `--prio-fee`  | `ETH_PRIO_FEE`  |              | EIP-1559 priority fee (miner tip) |
 | `--value`     | `ETH_VALUE`     | `0`          | ether value                       |

src/seth/libexec/seth/seth-mktx

@@ -13,20 +13,36 @@ if [[ $2 ]]; then
   data=$(seth calldata "${@:2}")
 fi
 
+data=${data:-0x}
+
+if [[ -z "$SETH_CREATE" ]]; then
+  TO=$(seth --to-address "$1")
+fi
+
+if [[ -z "$ETH_GAS" ]]; then
+  jshon+=(-n {})
+  [[ $TO ]] && jshon+=(-s "$TO" -i to)
+  jshon+=(-s "$data" -i data)
+  # shellcheck disable=SC2207
+  jshon+=($(SETH_PARAMS_NO_GAS=1 seth --send-params))
+  jshon+=(-i append)
+  ETH_GAS=$(seth rpc eth_estimateGas -- "${jshon[@]}")
+fi
+
 args=(
   --from "$(seth --to-address "$ETH_FROM")"
   --nonce "${ETH_NONCE:-$(seth nonce "$ETH_FROM")}"
   --chain-id "$(seth chain-id)"
   --gas-price "${ETH_GAS_PRICE:-$(seth gas-price)}"
-  --gas-limit "${ETH_GAS:-200000}"
+  --gas-limit "$ETH_GAS"
   --value "$value"
-  --data "${data:-0x}"
+  --data "$data"
 )
 
 if [[ $SETH_CREATE ]]; then
   args+=(--create)
 else
-  args+=(--to "$(seth --to-address "$1")")
+  args+=(--to "$TO")
 fi
 
 if [[ $ETH_PRIO_FEE ]]; then

src/seth/libexec/seth/seth-send

@@ -24,7 +24,7 @@ set -e
 [[ $ETH_FROM ]] ||
 seth --fail "${0##*/}: error: \`ETH_FROM' not set; send from which account?"
 [[ $ETH_GAS ]] ||
-echo >&2 "${0##*/}: warning: \`ETH_GAS' not set; using default gas amount"
+echo >&2 "${0##*/}: warning: \`ETH_GAS' not set; using estimated gas amount"
 if [[ $SETH_RESEND ]]; then
   nonce=$(seth nonce "$ETH_FROM")
   export ETH_NONCE=$nonce