Handle ref and sha errors in pull_request_handler

[changelog:changed]
atomist-skills · Jun 7, 2021 · 5a229db · 5a229db
1 parent f4d3432
commit 5a229db
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Showing 4 changed files with 55 additions and 21 deletions.
diff --git a/lib/github/index.ts b/lib/github/index.ts
@@ -18,9 +18,12 @@ export { Check, CreateCheck, createCheck, UpdateCheck } from "./check";
 export { uploadCodeScanningResults } from "./code_scanning";
 export {
 	api,
+	BlobMode,
 	ContentEditor,
 	convergeLabel,
 	editContent,
+	EditContentError,
+	EditContentErrorCode,
 	formatCommitMarkers,
 	formatFooter,
 	formatMarkers,

diff --git a/lib/github/operation.ts b/lib/github/operation.ts
@@ -218,7 +218,7 @@ export async function editContent<D>(
 		!parameters.base
 	) {
 		throw new EditContentError(
-			"INVALID_PARAMETERS",
+			EditContentErrorCode.InvalidParameters,
 			"Required parameter missing",
 		);
 	}
@@ -242,13 +242,13 @@ export async function editContent<D>(
 		).data;
 	} catch (e) {
 		throw new EditContentError(
-			"INVALID_REF",
+			EditContentErrorCode.InvalidRef,
 			`Failed to read ref '${parameters.base}'`,
 		);
 	}
 	if (parameters.sha !== ref.object.sha) {
 		throw new EditContentError(
-			"INVALID_SHA",
+			EditContentErrorCode.InvalidSha,
 			`Ref '${parameters.base}' points to different commit '${ref.object.sha}'`,
 		);
 	}
@@ -283,7 +283,7 @@ export async function editContent<D>(
 			validatePath(path);
 			if (content === undefined) {
 				throw new EditContentError(
-					"INVALID_CONTENT",
+					EditContentErrorCode.InvalidContent,
 					"Content required",
 				);
 			}
@@ -391,18 +391,32 @@ export async function editContent<D>(
 	};
 }
 
+export enum EditContentErrorCode {
+	InvalidPath = "INVALID_PATH",
+	InvalidContent = "INVALID_CONTENT",
+	InvalidRef = "INVALID_REF",
+	InvalidSha = "INVALID_SHA",
+	InvalidParameters = "INVALID_PARAMETERS",
+}
+
 export class EditContentError extends Error {
-	constructor(public readonly code: string, public readonly message: string) {
+	constructor(
+		public readonly code: EditContentErrorCode,
+		public readonly message: string,
+	) {
 		super(message);
 	}
 }
 
 export function validatePath(name: string): void {
 	if (!name) {
-		throw new EditContentError("INVALID_PATH", `Path required`);
+		throw new EditContentError(
+			EditContentErrorCode.InvalidPath,
+			`Path required`,
+		);
 	} else if (!/^(?![/])[a-zA-Z0-9+_#/.-]+$/.test(name)) {
 		throw new EditContentError(
-			"INVALID_PATH",
+			EditContentErrorCode.InvalidPath,
 			`Invalid path '${name}' provided`,
 		);
 	}

diff --git a/lib/policy/index.ts b/lib/policy/index.ts
@@ -30,4 +30,7 @@ export {
 	toConclusion,
 	toSeverity,
 } from "./policy";
-export { pullRequestHandler } from "./pull_request_handler";
+export {
+	pullRequestHandler,
+	PullRequestHandlerResponse,
+} from "./pull_request_handler";
diff --git a/lib/policy/pull_request_handler.ts b/lib/policy/pull_request_handler.ts
@@ -19,6 +19,8 @@ import {
 	api,
 	ContentEditor,
 	editContent,
+	EditContentError,
+	EditContentErrorCode,
 	formatFooter,
 	formatMarkers,
 } from "../github/operation";
@@ -27,9 +29,9 @@ import { chain, createRef, CreateRepositoryId } from "../handler/util";
 import { AuthenticatedRepositoryId } from "../repository/id";
 import * as status from "../status";
 import { hash } from "../util";
+import map = require("lodash.map");
 
 import uniq = require("lodash.uniq");
-import map = require("lodash.map");
 
 export interface PullRequestHandlerResponse<S, C, D = string> {
 	commit: {
@@ -92,17 +94,29 @@ export function pullRequestHandler<S, C, D = string>(parameters: {
 
 			const gh = api(ctx.chain.id);
 
-			const editResult = await editContent<D>(
-				{
-					credential: ctx.chain.id.credential,
-					owner: ctx.chain.id.owner,
-					repo: ctx.chain.id.repo,
-					sha: ctx.chain.id.sha,
-					base: ctx.chain.id.branch,
-					force: true,
-				},
-				...result.commit.editors,
-			);
+			let editResult;
+			try {
+				editResult = await editContent<D>(
+					{
+						credential: ctx.chain.id.credential,
+						owner: ctx.chain.id.owner,
+						repo: ctx.chain.id.repo,
+						sha: ctx.chain.id.sha,
+						base: ctx.chain.id.branch,
+						force: true,
+					},
+					...result.commit.editors,
+				);
+			} catch (e) {
+				if (e instanceof EditContentError) {
+					if (e.code === EditContentErrorCode.InvalidSha) {
+						return status.success(`Branch moved on`).hidden();
+					} else if (e.code === EditContentErrorCode.InvalidRef) {
+						return status.success(`Ref not found`).hidden();
+					}
+				}
+				throw e;
+			}
 
 			if (editResult.sha !== ctx.chain.id.sha) {
 				const pullRequest = await result.pullRequest(
@@ -199,7 +213,7 @@ ${formatMarkers(ctx, `atomist-diff:${diffHash}`)}
 					}](${pr.html_url})`,
 				);
 			} else {
-				return status.success(`No changes to push`);
+				return status.success(`No changes to push`).hidden();
 			}
 		},
 	) as EventHandler<S, C>;