Initial provider implementation (#18)

This brings over the initial buildx prototype from pulumi/pulumi-docker
and fixes various build and release issues.

provider/internal/dedent_test.go

@@ -0,0 +1,51 @@
+// Copyright 2024, Pulumi Corporation.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package internal
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestDedent(t *testing.T) {
+	t.Parallel()
+	tests := []struct {
+		name  string
+		given string
+		want  string
+	}{
+		{
+			name: "simple case",
+			given: `
+		An optional map of named build-time argument variables to set during
+		the Docker build. This flag allows you to pass build-time variables that
+		can be accessed like environment variables inside the "RUN"
+		instruction.`,
+			want: `An optional map of named build-time argument variables to set during
+the Docker build. This flag allows you to pass build-time variables that
+can be accessed like environment variables inside the ` + "`RUN`\n" + `instruction.`,
+		},
+	}
+
+	for _, tt := range tests {
+		tt := tt
+		t.Run(tt.name, func(t *testing.T) {
+			t.Parallel()
+			actual := dedent(tt.given)
+			assert.Equal(t, tt.want, actual)
+		})
+	}
+}