Use idiomatic bash

.github/workflows/labeler.yml

@@ -7,7 +7,7 @@ jobs:
     runs-on: ubuntu-latest
     name: Label the PR size
     steps:
-      - uses: codelytv/pr-size-labeler@v1
+      - uses: codelytv/pr-size-labeler@improvements
         with:
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
           xs_max_size: '10'

Dockerfile

@@ -3,5 +3,6 @@ FROM alpine:3.10
 RUN apk add --no-cache bash curl jq bc
 
 ADD entrypoint.sh /entrypoint.sh
+ADD src /src
 
 ENTRYPOINT ["/entrypoint.sh"]

entrypoint.sh

@@ -1,76 +1,16 @@
-#!/bin/bash
-set -e
+#!/usr/bin/env bash
+set -euo pipefail
 
-if [[ -z "$GITHUB_REPOSITORY" ]]; then
-  echo "The env variable GITHUB_REPOSITORY is required."
-  exit 1
+PR_SIZE_LABELER_HOME="$(cd "$(dirname "${BASH_SOURCE[0]}")" >/dev/null 2>&1 && pwd)"
+
+if [ "$PR_SIZE_LABELER_HOME" == "/" ]; then
+  PR_SIZE_LABELER_HOME=""
 fi
 
-if [[ -z "$GITHUB_EVENT_PATH" ]]; then
-  echo "The env variable GITHUB_EVENT_PATH is required."
-  exit 1
-fi
+export PR_SIZE_LABELER_HOME
 
-GITHUB_TOKEN="$1"
+source "$PR_SIZE_LABELER_HOME/src/main.sh"
 
-xs_max_size="$2"
-s_max_size="$3"
-m_max_size="$4"
-l_max_size="$5"
-
-fail_if_xl="$6"
-
-URI="https://api.github.com"
-API_HEADER="Accept: application/vnd.github.v3+json"
-AUTH_HEADER="Authorization: token ${GITHUB_TOKEN}"
-
-echo "GitHub event"
-echo "$GITHUB_EVENT_PATH"
-
-number=$(jq --raw-output .pull_request.number "$GITHUB_EVENT_PATH")
-
-autolabel() {
-  # https://developer.github.com/v3/pulls/#get-a-single-pull-request
-  # Example: https://api.github.com/repos/CodelyTV/java-ddd-example/pulls/7
-  body=$(curl -sSL -H "${AUTH_HEADER}" -H "${API_HEADER}" "${URI}/repos/${GITHUB_REPOSITORY}/pulls/${number}")
-
-  additions=$(echo "$body" | jq '.additions')
-  deletions=$(echo "$body" | jq '.deletions')
-  total_modifications=$(echo "$additions + $deletions" | bc)
-  label_to_add=$(label_for "$total_modifications")
-
-  echo "Labeling pull request with $label_to_add"
-
-  curl -sSL \
-    -H "${AUTH_HEADER}" \
-    -H "${API_HEADER}" \
-    -X POST \
-    -H "Content-Type: application/json" \
-    -d "{\"labels\":[\"${label_to_add}\"]}" \
-    "${URI}/repos/${GITHUB_REPOSITORY}/issues/${number}/labels"
-
-  if [ "$label_to_add" == "size/xl" ] && [ "$fail_if_xl" == "true" ]; then
-    echo "Pr is xl, please, short this!!"
-    exit 1
-  fi
-}
-
-label_for() {
-  if [ "$1" -lt "$xs_max_size" ]; then
-    label="size/xs"
-  elif [ "$1" -lt "$s_max_size" ]; then
-    label="size/s"
-  elif [ "$1" -lt "$m_max_size" ]; then
-    label="size/m"
-  elif [ "$1" -lt "$l_max_size" ]; then
-    label="size/l"
-  else
-    label="size/xl"
-  fi
-
-  echo "$label"
-}
-
-autolabel
+main "$@"
 
 exit $?

src/ensure.sh

@@ -0,0 +1,18 @@
+#!/usr/bin/env bash
+
+ensure::env_variable_exist() {
+  if [[ -z "${!1}" ]]; then
+    echoerr "The env variable $1 is required."
+    exit 1
+  fi
+}
+
+ensure::total_args() {
+  local -r received_args=$(echo "$# - 1" | bc)
+  local -r expected_args=$1
+
+  if ((received_args != expected_args)); then
+    echoerr "Illegal number of parameters, $expected_args expected but $received_args found"
+    exit 1
+  fi
+}

src/github.sh

@@ -0,0 +1,26 @@
+#!/usr/bin/env bash
+
+GITHUB_API_URI="https://api.github.com"
+GITHUB_API_HEADER="Accept: application/vnd.github.v3+json"
+
+github::calculate_total_modifications() {
+  local -r body=$(curl -sSL -H "Authorization: token $GITHUB_TOKEN" -H "$GITHUB_API_HEADER" "$GITHUB_API_URI/repos/$GITHUB_REPOSITORY/pulls/$1")
+
+  local -r additions=$(echo "$body" | jq '.additions')
+  local -r deletions=$(echo "$body" | jq '.deletions')
+
+  echo "$additions + $deletions" | bc
+}
+
+github::add_label_to_pr() {
+  local -r pr_number=$1
+  local -r label_to_add=$2
+
+  curl -sSL \
+    -H "Authorization: token $GITHUB_TOKEN" \
+    -H "$GITHUB_API_HEADER" \
+    -X POST \
+    -H "Content-Type: application/json" \
+    -d "{\"labels\":[\"$label_to_add\"]}" \
+    "$GITHUB_API_URI/repos/$GITHUB_REPOSITORY/issues/$pr_number/labels"
+}

src/github_actions.sh

@@ -0,0 +1,5 @@
+#!/usr/bin/env bash
+
+github_actions::get_pr_number() {
+  jq --raw-output .pull_request.number "$GITHUB_EVENT_PATH"
+}

src/labeler.sh

@@ -0,0 +1,43 @@
+#!/usr/bin/env bash
+
+labeler::label() {
+  local -r fail_if_xl="$5"
+
+  local -r pr_number=$(github_actions::get_pr_number)
+  local -r total_modifications=$(github::calculate_total_modifications "$pr_number")
+
+  log::message "total modifications: $total_modifications"
+
+  local -r label_to_add=$(labeler::label_for "$total_modifications" "$@")
+
+  log::message "Labeling pull request with $label_to_add"
+
+  github::add_label_to_pr "$pr_number" "$label_to_add"
+
+  if [ "$label_to_add" == "size/xl" ] && [ "$fail_if_xl" == "true" ]; then
+    echoerr "Pr is xl, please, short this!!"
+    exit 1
+  fi
+}
+
+labeler::label_for() {
+  local -r total_modifications="$1"
+  local -r xs_max_size="$2"
+  local -r s_max_size="$3"
+  local -r m_max_size="$4"
+  local -r l_max_size="$5"
+
+  if [ "$total_modifications" -lt "$xs_max_size" ]; then
+    label="size/xs"
+  elif [ "$total_modifications" -lt "$s_max_size" ]; then
+    label="size/s"
+  elif [ "$total_modifications" -lt "$m_max_size" ]; then
+    label="size/m"
+  elif [ "$total_modifications" -lt "$l_max_size" ]; then
+    label="size/l"
+  else
+    label="size/xl"
+  fi
+
+  echo "$label"
+}

src/main.sh

@@ -0,0 +1,19 @@
+#!/usr/bin/env bash
+
+source "$PR_SIZE_LABELER_HOME/src/ensure.sh"
+source "$PR_SIZE_LABELER_HOME/src/github.sh"
+source "$PR_SIZE_LABELER_HOME/src/github_actions.sh"
+source "$PR_SIZE_LABELER_HOME/src/labeler.sh"
+source "$PR_SIZE_LABELER_HOME/src/misc.sh"
+
+main() {
+  ensure::env_variable_exist "GITHUB_REPOSITORY"
+  ensure::env_variable_exist "GITHUB_EVENT_PATH"
+  ensure::total_args 6 "$@"
+
+  export GITHUB_TOKEN="$1"
+
+  labeler::label "$2" "$3" "$4" "$5" "$6"
+
+  exit $?
+}

src/misc.sh

@@ -0,0 +1,9 @@
+#!/usr/bin/env bash
+
+echoerr() {
+   echo "$@" 1>&2
+}
+
+log::message() {
+  echo "$@"
+}