add formatter action

.JuliaFormatter.toml

@@ -0,0 +1,12 @@
+annotate_untyped_fields_with_any = false
+short_to_long_function_def = false
+whitespace_ops_in_indices = true
+remove_extra_newlines = true
+whitespace_in_kwargs = true
+always_use_return = false
+conditional_to_if = false
+align_struct_field = true
+align_conditional = true
+align_assignment = true
+align_pair_arrow = true
+import_to_using = false

.github/workflows/Format-check.yml

@@ -0,0 +1,39 @@
+name: format
+
+on:
+  push:
+    branches:
+      - 'master'
+      - 'release-'
+    tags: '*'
+  pull_request:
+
+jobs:
+  check:
+    runs-on: ${{ matrix.os }}
+    strategy:
+      matrix:
+        julia-version: ['1']
+        julia-arch: [x64]
+        os: [ubuntu-latest]
+    steps:
+      - uses: julia-actions/setup-julia@latest
+        with:
+          version: ${{ matrix.julia-version }}
+
+      - uses: actions/checkout@v2
+      - name: Install JuliaFormatter and format
+        run: |
+          julia -e 'using Pkg; Pkg.add(PackageSpec(name="JuliaFormatter"))'
+          julia -e 'using JuliaFormatter; format(["src", "test"], verbose=true)'
+      - name: Format check
+        run: |
+          julia -e '
+          out = Cmd(`git diff --name-only`) |> read |> String
+          if out == ""
+              exit(0)
+          else
+              @error "Some files have not been formatted !!!"
+              write(stdout, out)
+              exit(1)
+          end'