GitHub action (#687)

* Draft GitHub action

* Update action.yml

* Allow solc version selection

* Updation action.yml

.github/workflows/action.yml

@@ -0,0 +1,35 @@
+name: Action
+
+on:
+  push:
+    branches:
+      - master
+      - nix
+  pull_request:
+    branches:
+      - master
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v2
+
+      - name: Assert test
+        uses: ./action
+        with:
+          files: "examples/solidity/basic/assert.sol"
+          contract: "TestAssert"
+          config: "examples/solidity/basic/assert.yaml"
+          solc-version: 0.6.12
+          negate-exit-status: 1
+
+      - name: Multi-abi test
+        uses: ./action
+        with:
+          files: "examples/solidity/basic/multi-abi.sol"
+          contract: "B"
+          multi-abi: true
+          solc-version: 0.7.6
+          negate-exit-status: 1

action/Dockerfile

@@ -0,0 +1,5 @@
+FROM trailofbits/echidna
+RUN pip3 install solc-select
+COPY entrypoint.sh /entrypoint.sh
+RUN chmod ugo+x /entrypoint.sh
+ENTRYPOINT ["/entrypoint.sh"]

action/action.yml

@@ -0,0 +1,63 @@
+name: "Echidna"
+
+description: "Run echidna-test"
+
+inputs:
+  files:
+    description: "Solidity files to analyze"
+    required: true
+  contract:
+    description: "Contract to analyze"
+    required: false
+  config:
+    description: "Config file (CLI arguments override config options)"
+    required: false
+  format:
+    description: "Output format: json, text, none. Disables interactive UI"
+    required: false
+  corpus-dir:
+    description: "Directory to store corpus and coverage data"
+    required: false
+  check-asserts:
+    description: "Check asserts in the code"
+    required: false
+  multi-abi:
+    description: "Use multi-abi mode of testing"
+    required: false
+  test-limit:
+    description: "Number of sequences of transactions to generate during testing"
+    required: false
+  shrink-limit:
+    description: "Number of tries to attempt to shrink a failing sequence of transactions"
+    required: false
+  seq-len:
+    description: "Number of transactions to generate during testing"
+    required: false
+  contract-addr:
+    description: "Address to deploy the contract to test"
+    required: false
+  deployer:
+    description: "Address of the deployer of the contract to test"
+    required: false
+  sender:
+    description: "Addresses to use for the transactions sent during testing"
+    required: false
+  seed:
+    description: "Run with a specific seed"
+    required: false
+  crytic-args:
+    description: "Additional arguments to use in crytic-compile for the compilation of the contract to test"
+    required: false
+  solc-args:
+    description: "Additional arguments to use in solc for the compilation of the contract to test"
+    required: false
+  solc-version:
+    description: "Version of the Solidity compiler to use"
+    required: false
+  negate-exit-status:
+    description: "Apply logical NOT to echidna-test's exit status (for testing the action)"
+    required: false
+
+runs:
+  using: "docker"
+  image: "Dockerfile"

action/entrypoint.sh

@@ -0,0 +1,47 @@
+#! /bin/bash
+
+set -eu
+
+export PYTHONPATH=/root/.local/lib/python3.6/site-packages
+
+OPTIONS="contract config format corpus-dir test-limit shrink-limit seq-len \
+contract-addr deployer sender seed crytic-args solc-args"
+
+SWITCHES="check-asserts multi-abi"
+
+# smoelius: `get` works for non-standard variable names like `INPUT_CORPUS-DIR`.
+get() {
+    env | sed -n "s/^$1=\(.*\)/\1/;T;p"
+}
+
+CMD=(echidna-test "$INPUT_FILES")
+
+for OPTION in $OPTIONS; do
+    NAME=INPUT_"${OPTION^^}"
+    VALUE="$(get "$NAME")"
+    if [[ -n "$VALUE" ]]; then
+        CMD+=(--"$OPTION" "$VALUE")
+    fi
+done
+
+for SWITCH in $SWITCHES; do
+    NAME=INPUT_"${SWITCH^^}"
+    VALUE="$(get "$NAME")"
+    if [[ -n "$VALUE" ]]; then
+        CMD+=(--"$SWITCH")
+    fi
+done
+
+SOLC_VERSION="$(get 'INPUT_SOLC-VERSION')"
+if [[ -n "$SOLC_VERSION" ]]; then
+    solc-select install "$SOLC_VERSION"
+    solc-select use "$SOLC_VERSION"
+fi
+
+echo "${CMD[@]}" >&2
+
+if [[ -n "$(get 'INPUT_NEGATE-EXIT-STATUS')" ]]; then
+    ! "${CMD[@]}"
+else
+    "${CMD[@]}"
+fi