Add PR labels based on files changed (#1127)

* Add PR labels based on files changed

* Remove platform code

.github/workflows/pr-labels.yaml

@@ -0,0 +1,24 @@
+name: PR labels
+
+on: [pull_request]
+
+
+jobs:
+  pr-label:
+    runs-on: ubuntu-latest
+    name: PR label
+    steps:
+    - uses: actions/checkout@v2
+      with:
+        fetch-depth: 0
+    - id: pr_labels
+      run: script/pr-labels ${{ github.event.pull_request.base.sha }} ${{ github.event.pull_request.head.sha }}
+    - uses: octokit/request-action@v2.0.7
+      if: ${{ steps.pr_labels.outputs.labels != '[""]' }}
+      with:
+        route: POST /repos/:repository/issues/:number/labels
+        number: ${{ github.event.number }}
+        repository: ${{ github.repository }}
+        labels: ${{ steps.pr_labels.outputs.labels }}
+      env:
+        GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}

script/pr-labels

@@ -0,0 +1,29 @@
+#!/bin/bash
+
+components=()
+for c_diff in $(git diff ${1}..${2} --name-only esphome/components); do
+  base=${c_diff#esphome/components/}
+  component=`dirname ${base}`
+
+  if [[ "${component}" == "." ]]; then
+    component=${platform}
+  fi
+
+  if [[ ! "${components[@]}" =~ "${component}" ]]; then
+    components+=($component)
+  fi
+done
+
+labels=()
+
+echo "Components:"
+for component in ${components[@]}; do
+  echo "  ${component}"
+  labels+=("component: $component")
+done
+
+echo "Labels: ${labels[@]}"
+
+output=$(printf '%s\n' "${labels[@]}" | jq -R . | jq -c -s .)
+
+echo "::set-output name=labels::${output}"