Handle errors as unknown (not any)

Typescript started handling `error: unknown` in v4.0. It hadn't been
enforced strictly until now.

.eslintrc.json

@@ -46,6 +46,14 @@
       "@typescript-eslint/no-shadow": "error",
       "no-shadow": "off"
     },
+    "overrides": [
+      {
+        "files": ["*.ts"],
+        "rules": {
+          "no-undef": "off"
+        }
+      }
+    ],
     "env": {
       "node": true,
       "es6": true,

src/api-client.ts

@@ -70,7 +70,7 @@ export class ApiClient {
       }
 
       return res.data.data.attributes.credentials
-    } catch (error) {
+    } catch (error: unknown) {
       if (axios.isAxiosError(error)) {
         const err = error
         throw new CredentialFetchingError(

src/cleanup.ts

@@ -21,8 +21,10 @@ export async function run(cutoff = '24h'): Promise<void> {
     await docker.pruneContainers({filters: untilFilter})
     await cleanupOldImageVersions(docker, UPDATER_IMAGE_NAME)
     await cleanupOldImageVersions(docker, PROXY_IMAGE_NAME)
-  } catch (error) {
-    core.error(`Error cleaning up: ${error.message}`)
+  } catch (error: unknown) {
+    if (error instanceof Error) {
+      core.error(`Error cleaning up: ${error.message}`)
+    }
   }
 }
 
@@ -62,11 +64,9 @@ export async function cleanupOldImageVersions(
         core.info(`Removing image ${imageInfo.Id}`)
         try {
           await docker.getImage(imageInfo.Id).remove()
-        } catch (error) {
-          if (error.statusCode === 409) {
-            core.info(
-              `Unable to remove ${imageInfo.Id} as it is currently in use`
-            )
+        } catch (error: unknown) {
+          if (error instanceof Error) {
+            core.info(`Unable to remove ${imageInfo.Id} -- ${error.message}`)
           }
         }
       }

src/image-service.ts

@@ -36,8 +36,8 @@ export const ImageService = {
         core.info(`Resolved ${imageName} to existing ${image.RepoDigests}`)
         return
       } // else fallthrough to pull
-    } catch (e) {
-      if (!e.message.includes('no such image')) {
+    } catch (e: unknown) {
+      if (e instanceof Error && !e.message.includes('no such image')) {
         throw e
       } // else fallthrough to pull
     }

src/inputs.ts

@@ -113,15 +113,19 @@ function directoryExistsSync(directoryPath: string): boolean {
 
   try {
     stats = fs.statSync(directoryPath)
-  } catch (error) {
-    if (error.code === 'ENOENT') {
+    return stats.isDirectory()
+  } catch (error: unknown) {
+    if (isNodeError(error) && error.code === 'ENOENT') {
       return false
+    } else if (error instanceof Error) {
+      throw new Error(
+        `Encountered an error when checking whether path '${directoryPath}' exists: ${error.message}`
+      )
     }
-
-    throw new Error(
-      `Encountered an error when checking whether path '${directoryPath}' exists: ${error.message}`
-    )
   }
+  return false
+}
 
-  return stats.isDirectory()
+function isNodeError(error: any): error is NodeJS.ErrnoException {
+  return error instanceof Error
 }

src/main.ts

@@ -59,22 +59,24 @@ export async function run(context: Context): Promise<void> {
       try {
         await ImageService.pull(UPDATER_IMAGE_NAME)
         await ImageService.pull(PROXY_IMAGE_NAME)
-      } catch (error: any) {
-        await failJob(
-          apiClient,
-          'Error fetching updater images',
-          error,
-          DependabotErrorType.Image
-        )
-        return
+      } catch (error: unknown) {
+        if (error instanceof Error) {
+          await failJob(
+            apiClient,
+            'Error fetching updater images',
+            error,
+            DependabotErrorType.Image
+          )
+          return
+        }
       }
       core.endGroup()
 
       try {
         core.info('Starting update process')
 
         await updater.runUpdater()
-      } catch (error: any) {
+      } catch (error: unknown) {
         // If we have encountered a UpdaterFetchError, the Updater will already have
         // reported the error and marked the job as processed, so we only need to
         // set an exit status.
@@ -85,7 +87,7 @@ export async function run(context: Context): Promise<void> {
           )
           botSay('finished: unable to fetch files')
           return
-        } else {
+        } else if (error instanceof Error) {
           await failJob(
             apiClient,
             'Dependabot encountered an error performing the update',
@@ -96,15 +98,15 @@ export async function run(context: Context): Promise<void> {
         }
       }
       botSay('finished')
-    } catch (error: any) {
+    } catch (error: unknown) {
       if (error instanceof CredentialFetchingError) {
         await failJob(
           apiClient,
           'Dependabot was unable to retrieve job credentials',
           error,
           DependabotErrorType.UpdateRun
         )
-      } else {
+      } else if (error instanceof Error) {
         await failJob(
           apiClient,
           'Dependabot was unable to start the update',
@@ -114,14 +116,16 @@ export async function run(context: Context): Promise<void> {
 
       return
     }
-  } catch (error) {
-    // If we've reached this point, we do not have a viable
-    // API client to report back to Dependabot API.
-    //
-    // We output the raw error in the Action logs and defer
-    // to workflow_run monitoring to detect the job failure.
-    setFailed('Dependabot encountered an unexpected problem', error)
-    botSay('finished: unexpected error')
+  } catch (error: unknown) {
+    if (error instanceof Error) {
+      // If we've reached this point, we do not have a viable
+      // API client to report back to Dependabot API.
+      //
+      // We output the raw error in the Action logs and defer
+      // to workflow_run monitoring to detect the job failure.
+      setFailed('Dependabot encountered an unexpected problem', error)
+      botSay('finished: unexpected error')
+    }
   }
 }