bake class to parse definitions and handle exporters type

Signed-off-by: CrazyMax <crazy-max@users.noreply.github.com>

src/buildx/bake.ts

@@ -0,0 +1,74 @@
+/**
+ * Copyright 2023 actions-toolkit authors
+ *
+ * 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.
+ */
+
+import {Buildx} from './buildx';
+import {Exec} from '../exec';
+import {Inputs} from './inputs';
+
+import {BakeDefinition} from '../types/bake';
+
+export interface BakeOpts {
+  buildx?: Buildx;
+}
+
+export class Bake {
+  private readonly buildx: Buildx;
+
+  constructor(opts?: BakeOpts) {
+    this.buildx = opts?.buildx || new Buildx();
+  }
+
+  public async parseDefinitions(files: Array<string>, targets: Array<string>): Promise<BakeDefinition> {
+    const args = ['bake'];
+    if (files) {
+      for (const file of files) {
+        args.push('--file', file);
+      }
+    }
+
+    const printCmd = await this.buildx.getCommand([...args, '--print', ...targets]);
+    return await Exec.getExecOutput(printCmd.command, printCmd.args, {
+      ignoreReturnCode: true,
+      silent: true
+    }).then(res => {
+      if (res.stderr.length > 0 && res.exitCode != 0) {
+        throw new Error(res.stderr);
+      }
+      return <BakeDefinition>JSON.parse(res.stdout.trim());
+    });
+  }
+
+  public static hasLocalExporter(def: BakeDefinition): boolean {
+    return Inputs.hasExporterType('local', Bake.exporters(def));
+  }
+
+  public static hasTarExporter(def: BakeDefinition): boolean {
+    return Inputs.hasExporterType('tar', Bake.exporters(def));
+  }
+
+  public static hasDockerExporter(def: BakeDefinition, load?: boolean): boolean {
+    return load || Inputs.hasExporterType('docker', Bake.exporters(def));
+  }
+
+  private static exporters(def: BakeDefinition): Array<string> {
+    const exporters = new Array<string>();
+    for (const key in def.target) {
+      const target = def.target[key];
+      exporters.push(...target.output);
+    }
+    return exporters;
+  }
+}