feat(issue-62): make cherry-pick strategy configurable (#63)

fix https://github.com/kiegroup/git-backporting/issues/62

src/service/args/args-parser.ts

@@ -39,6 +39,8 @@ export default abstract class ArgsParser {
       labels: this.getOrDefault(args.labels, []),
       inheritLabels: this.getOrDefault(args.inheritLabels, false),
       squash: this.getOrDefault(args.squash, true),
+      strategy: this.getOrDefault(args.strategy),
+      strategyOption: this.getOrDefault(args.strategyOption),
     };
   }
 }

src/service/args/args.types.ts

@@ -19,4 +19,6 @@ export interface Args {
   labels?: string[], // backport pr labels
   inheritLabels?: boolean, // if true inherit labels from original pr
   squash?: boolean, // if false use squashed/merged commit otherwise backport all commits as part of the pr
+  strategy?: string, // cherry-pick merge strategy
+  strategyOption?: string, // cherry-pick merge strategy option
 }

src/service/args/cli/cli-args-parser.ts

@@ -27,6 +27,8 @@ export default class CLIArgsParser extends ArgsParser {
       .option("--labels <labels>", "comma separated list of labels to be assigned to the backported pull request", getAsCommaSeparatedList)
       .option("--inherit-labels", "if true the backported pull request will inherit labels from the original one")
       .option("--no-squash", "if provided the tool will backport all commits as part of the pull request")
+      .option("--strategy <strategy>", "cherry-pick merge strategy, default to 'recursive'", undefined)
+      .option("--strategy-option <strategy-option>", "cherry-pick merge strategy option, default to 'theirs'")
       .option("-cf, --config-file <config-file>", "configuration file containing all valid options, the json must match Args interface");
   }
 
@@ -58,6 +60,8 @@ export default class CLIArgsParser extends ArgsParser {
         labels: opts.labels,
         inheritLabels: opts.inheritLabels,
         squash: opts.squash,
+        strategy: opts.strategy,
+        strategyOption: opts.strategyOption,
       };
     }
 

src/service/args/gha/gha-args-parser.ts

@@ -30,6 +30,8 @@ export default class GHAArgsParser extends ArgsParser {
         labels: getAsCommaSeparatedList(getInput("labels")),
         inheritLabels: getAsBooleanOrDefault(getInput("inherit-labels")),
         squash: !getAsBooleanOrDefault(getInput("no-squash")),
+        strategy: getOrUndefined(getInput("strategy")),
+        strategyOption: getOrUndefined(getInput("strategy-option")),
       };
     }
 

src/service/configs/configs.types.ts

@@ -16,6 +16,8 @@ export interface Configs {
   git: LocalGit,
   folder: string,
   targetBranch: string,
+  mergeStrategy?: string, // cherry-pick merge strategy
+  mergeStrategyOption?: string, // cherry-pick merge strategy option
   originalPullRequest: GitPullRequest,
   backportPullRequest: GitPullRequest,
  }

src/service/configs/pullrequest/pr-configs-parser.ts

@@ -30,6 +30,8 @@ export default class PullRequestConfigsParser extends ConfigsParser {
       auth: args.auth,
       folder: `${folder.startsWith("/") ? "" : process.cwd() + "/"}${args.folder ?? this.getDefaultFolder()}`,
       targetBranch: args.targetBranch,
+      mergeStrategy: args.strategy,
+      mergeStrategyOption: args.strategyOption,
       originalPullRequest: pr,
       backportPullRequest: this.getDefaultBackportPullRequest(pr, args),
       git: {

src/service/git/git-cli.ts

@@ -105,9 +105,20 @@ export default class GitCLIService {
    * @param cwd repository in which the sha should be cherry picked to
    * @param sha commit sha
    */
-  async cherryPick(cwd: string, sha: string): Promise<void> {
+  async cherryPick(cwd: string, sha: string, strategy = "recursive", strategyOption = "theirs"): Promise<void> {
     this.logger.info(`Cherry picking ${sha}.`);
-    await this.git(cwd).raw(["cherry-pick", "-m", "1", "--strategy=recursive", "--strategy-option=theirs", sha]);
+    
+    const options = ["cherry-pick", "-m", "1", `--strategy=${strategy}`, `--strategy-option=${strategyOption}`, sha];
+    try {
+      await this.git(cwd).raw(options);
+    } catch(error) {
+      const diff = await this.git(cwd).diff();
+      if (diff) {
+        throw new Error(`${error}\r\nShowing git diff:\r\n` + diff);
+      }
+
+      throw error;
+    }
   }
 
   /**

src/service/runner/runner.ts

@@ -99,7 +99,7 @@ export default class Runner {
     // 7. apply all changes to the new branch
     this.logger.debug("Cherry picking commits..");
     for (const sha of originalPR.commits!) {
-      await git.cherryPick(configs.folder, sha);
+      await git.cherryPick(configs.folder, sha, configs.mergeStrategy, configs.mergeStrategyOption);
     }
 
     const backport: BackportPullRequest = {