Add toError utility function (#523)

* Add asError utility function

* Rename to toError

16 files changed, 85 insertions, 27 deletions

diff --git a/dev/dictionary-validate.js b/dev/dictionary-validate.js
index 51edcc50..3727310e 100644
--- a/dev/dictionary-validate.js
+++ b/dev/dictionary-validate.js
@@ -23,6 +23,7 @@ import {performance} from 'perf_hooks';
 import {fileURLToPath} from 'url';
 import {parseJson} from './json.js';
 import {createJsonSchema} from './schema-validate.js';
+import {toError} from './to-error.js';
 
 const dirname = path.dirname(fileURLToPath(import.meta.url));
 
@@ -47,7 +48,7 @@ async function validateDictionaryBanks(mode, zip, fileNameFormat, schema) {
     try {
         jsonSchema = createJsonSchema(mode, schema);
     } catch (e) {
-        const e2 = e instanceof Error ? e : new Error(`${e}`);
+        const e2 = toError(e);
         e2.message += `\n(in file ${fileNameFormat})}`;
         throw e2;
     }
@@ -62,7 +63,7 @@ async function validateDictionaryBanks(mode, zip, fileNameFormat, schema) {
         try {
             jsonSchema.validate(data);
         } catch (e) {
-            const e2 = e instanceof Error ? e : new Error(`${e}`);
+            const e2 = toError(e);
             e2.message += `\n(in file ${fileName})}`;
             throw e2;
         }
@@ -92,7 +93,7 @@ export async function validateDictionary(mode, archive, schemas) {
         const jsonSchema = createJsonSchema(mode, schemas.index);
         jsonSchema.validate(index);
     } catch (e) {
-        const e2 = e instanceof Error ? e : new Error(`${e}`);
+        const e2 = toError(e);
         e2.message += `\n(in file ${indexFileName})}`;
         throw e2;
     }
diff --git a/dev/to-error.js b/dev/to-error.js
new file mode 100644
index 00000000..1cc84f50
--- /dev/null
+++ b/dev/to-error.js
@@ -0,0 +1,18 @@
+/*
+ * Copyright (C) 2023  Yomitan Authors
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+export {toError} from '../ext/js/core/to-error.js';
diff --git a/ext/js/comm/mecab.js b/ext/js/comm/mecab.js
index 6d0f3f40..f3ad7b51 100644
--- a/ext/js/comm/mecab.js
+++ b/ext/js/comm/mecab.js
@@ -17,6 +17,7 @@
  */
 
 import {EventListenerCollection} from '../core.js';
+import {toError} from '../core/to-error.js';
 
 /**
  * This class is used to connect Yomitan to a native component that is
@@ -235,7 +236,7 @@ export class Mecab {
         try {
             await this._setupPortPromise;
         } catch (e) {
-            throw new Error(e instanceof Error ? e.message : `${e}`);
+            throw toError(e);
         }
     }
 
diff --git a/ext/js/core/to-error.js b/ext/js/core/to-error.js
new file mode 100644
index 00000000..4866c3da
--- /dev/null
+++ b/ext/js/core/to-error.js
@@ -0,0 +1,26 @@
+/*
+ * Copyright (C) 2023  Yomitan Authors
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+/**
+ * Utility function to convert an unknown value to an error.
+ * This is useful for try-catch situations where the catch parameter has the `unknown` type.
+ * @param {unknown} value
+ * @returns {Error}
+ */
+export function toError(value) {
+    return value instanceof Error ? value : new Error(`${value}`);
+}
diff --git a/ext/js/dictionary/dictionary-importer.js b/ext/js/dictionary/dictionary-importer.js
index 2c0c7e9c..bfd7a8b2 100644
--- a/ext/js/dictionary/dictionary-importer.js
+++ b/ext/js/dictionary/dictionary-importer.js
@@ -27,6 +27,7 @@ import {
 import {stringReverse} from '../core.js';
 import {ExtensionError} from '../core/extension-error.js';
 import {parseJson} from '../core/json.js';
+import {toError} from '../core/to-error.js';
 import {MediaUtil} from '../media/media-util.js';
 
 const ajvSchemas = /** @type {import('dictionary-importer').CompiledSchemaValidators} */ (/** @type {unknown} */ (ajvSchemas0));
@@ -206,7 +207,7 @@ export class DictionaryImporter {
                 try {
                     await dictionaryDatabase.bulkAdd(objectStoreName, entries, i, count);
                 } catch (e) {
-                    errors.push(e instanceof Error ? e : new Error(`${e}`));
+                    errors.push(toError(e));
                 }
 
                 this._progressData.index += count;
diff --git a/ext/js/display/display-anki.js b/ext/js/display/display-anki.js
index 759998c4..77ba7ffb 100644
--- a/ext/js/display/display-anki.js
+++ b/ext/js/display/display-anki.js
@@ -17,6 +17,7 @@
  */
 
 import {EventListenerCollection, deferPromise} from '../core.js';
+import {toError} from '../core/to-error.js';
 import {AnkiNoteBuilder} from '../data/anki-note-builder.js';
 import {AnkiUtil} from '../data/anki-util.js';
 import {PopupMenu} from '../dom/popup-menu.js';
@@ -159,7 +160,7 @@ export class DisplayAnki {
             try {
                 ({note: note, errors, requirements} = await this._createNote(dictionaryEntry, mode, []));
             } catch (e) {
-                errors = [e instanceof Error ? e : new Error(`${e}`)];
+                errors = [toError(e)];
             }
             /** @type {import('display-anki').AnkiNoteLogData} */
             const entry = {mode, note};
@@ -174,7 +175,7 @@ export class DisplayAnki {
 
         return {
             ankiNoteData,
-            ankiNoteDataException: ankiNoteDataException instanceof Error ? ankiNoteDataException : new Error(`${ankiNoteDataException}`),
+            ankiNoteDataException: toError(ankiNoteDataException),
             ankiNotes
         };
     }
@@ -490,7 +491,7 @@ export class DisplayAnki {
                 addNoteOkay = true;
             } catch (e) {
                 allErrors.length = 0;
-                allErrors.push(e instanceof Error ? e : new Error(`${e}`));
+                allErrors.push(toError(e));
             }
 
             if (addNoteOkay) {
@@ -501,7 +502,7 @@ export class DisplayAnki {
                         try {
                             await yomitan.api.suspendAnkiCardsForNote(noteId);
                         } catch (e) {
-                            allErrors.push(e instanceof Error ? e : new Error(`${e}`));
+                            allErrors.push(toError(e));
                         }
                     }
                     button.disabled = true;
@@ -509,7 +510,7 @@ export class DisplayAnki {
                 }
             }
         } catch (e) {
-            allErrors.push(e instanceof Error ? e : new Error(`${e}`));
+            allErrors.push(toError(e));
         } finally {
             progressIndicatorVisible.clearOverride(overrideToken);
         }
@@ -647,7 +648,7 @@ export class DisplayAnki {
             }
         } catch (e) {
             infos = this._getAnkiNoteInfoForceValue(notes, false);
-            ankiError = e instanceof Error ? e : new Error(`${e}`);
+            ankiError = toError(e);
         }
 
         /** @type {import('display-anki').DictionaryEntryDetails[]} */
@@ -855,11 +856,11 @@ export class DisplayAnki {
             await yomitan.api.noteView(noteIds[0], this._noteGuiMode, false);
         } catch (e) {
             const displayErrors = (
-                e instanceof Error && e.message === 'Mode not supported' ?
+                toError(e).message === 'Mode not supported' ?
                 [this._display.displayGenerator.instantiateTemplateFragment('footer-notification-anki-view-note-error')] :
                 void 0
             );
-            this._showErrorNotification([e instanceof Error ? e : new Error(`${e}`)], displayErrors);
+            this._showErrorNotification([toError(e)], displayErrors);
             return;
         }
     }
diff --git a/ext/js/display/display.js b/ext/js/display/display.js
index ff77d203..7e7dd426 100644
--- a/ext/js/display/display.js
+++ b/ext/js/display/display.js
@@ -21,6 +21,7 @@ import {FrameEndpoint} from '../comm/frame-endpoint.js';
 import {DynamicProperty, EventDispatcher, EventListenerCollection, clone, deepEqual, log, promiseTimeout} from '../core.js';
 import {extendApiMap, invokeApiMapHandler} from '../core/api-map.js';
 import {ExtensionError} from '../core/extension-error.js';
+import {toError} from '../core/to-error.js';
 import {PopupMenu} from '../dom/popup-menu.js';
 import {querySelectorNotNull} from '../dom/query-selector.js';
 import {ScrollElement} from '../dom/scroll-element.js';
@@ -787,7 +788,7 @@ export class Display extends EventDispatcher {
                     break;
             }
         } catch (e) {
-            this.onError(e instanceof Error ? e : new Error(`${e}`));
+            this.onError(toError(e));
         }
     }
 
@@ -922,7 +923,7 @@ export class Display extends EventDispatcher {
             };
             this.setContent(details);
         } catch (error) {
-            this.onError(error instanceof Error ? error : new Error(`${error}`));
+            this.onError(toError(error));
         }
     }
 
diff --git a/ext/js/display/option-toggle-hotkey-handler.js b/ext/js/display/option-toggle-hotkey-handler.js
index 73c92d59..ba4c8578 100644
--- a/ext/js/display/option-toggle-hotkey-handler.js
+++ b/ext/js/display/option-toggle-hotkey-handler.js
@@ -18,6 +18,7 @@
 
 import {generateId} from '../core.js';
 import {ExtensionError} from '../core/extension-error.js';
+import {toError} from '../core/to-error.js';
 import {yomitan} from '../yomitan.js';
 
 export class OptionToggleHotkeyHandler {
@@ -132,7 +133,7 @@ export class OptionToggleHotkeyHandler {
      * @returns {DocumentFragment}
      */
     _createErrorMessage(path, error) {
-        const message = error instanceof Error ? error.message : `${error}`;
+        const message = toError(error).message;
         const fragment = document.createDocumentFragment();
         const n1 = document.createElement('em');
         n1.textContent = path;
diff --git a/ext/js/dom/text-source-range.js b/ext/js/dom/text-source-range.js
index fd09fdda..7f4db4f2 100644
--- a/ext/js/dom/text-source-range.js
+++ b/ext/js/dom/text-source-range.js
@@ -16,6 +16,7 @@
  * along with this program.  If not, see <https://www.gnu.org/licenses/>.
  */
 
+import {toError} from '../core/to-error.js';
 import {DocumentUtil} from './document-util.js';
 import {DOMTextScanner} from './dom-text-scanner.js';
 
@@ -228,7 +229,7 @@ export class TextSourceRange {
             try {
                 return this._range.compareBoundaryPoints(Range.START_TO_START, other.range) === 0;
             } catch (e) {
-                if (e instanceof Error && e.name === 'WrongDocumentError') {
+                if (toError(e).name === 'WrongDocumentError') {
                     // This can happen with shadow DOMs if the ranges are in different documents.
                     return false;
                 }
diff --git a/ext/js/pages/settings/anki-controller.js b/ext/js/pages/settings/anki-controller.js
index d64034a5..c8daa85b 100644
--- a/ext/js/pages/settings/anki-controller.js
+++ b/ext/js/pages/settings/anki-controller.js
@@ -19,6 +19,7 @@
 import {AnkiConnect} from '../../comm/anki-connect.js';
 import {EventListenerCollection, log} from '../../core.js';
 import {ExtensionError} from '../../core/extension-error.js';
+import {toError} from '../../core/to-error.js';
 import {AnkiUtil} from '../../data/anki-util.js';
 import {querySelectorNotNull} from '../../dom/query-selector.js';
 import {SelectorObserver} from '../../dom/selector-observer.js';
@@ -409,7 +410,7 @@ export class AnkiController {
             this._sortStringArray(result);
             return [result, null];
         } catch (e) {
-            return [[], e instanceof Error ? e : new Error(`${e}`)];
+            return [[], toError(e)];
         }
     }
 
@@ -422,7 +423,7 @@ export class AnkiController {
             this._sortStringArray(result);
             return [result, null];
         } catch (e) {
-            return [[], e instanceof Error ? e : new Error(`${e}`)];
+            return [[], toError(e)];
         }
     }
 
@@ -487,7 +488,7 @@ export class AnkiController {
         try {
             await this._testAnkiNoteViewer(mode);
         } catch (e) {
-            this._setAnkiNoteViewerStatus(true, e instanceof Error ? e : new Error(`${e}`));
+            this._setAnkiNoteViewerStatus(true, toError(e));
             return;
         }
         this._setAnkiNoteViewerStatus(true, null);
diff --git a/ext/js/pages/settings/anki-templates-controller.js b/ext/js/pages/settings/anki-templates-controller.js
index 56e992b0..0c82cecc 100644
--- a/ext/js/pages/settings/anki-templates-controller.js
+++ b/ext/js/pages/settings/anki-templates-controller.js
@@ -17,6 +17,7 @@
  */
 
 import {ExtensionError} from '../../core/extension-error.js';
+import {toError} from '../../core/to-error.js';
 import {AnkiNoteBuilder} from '../../data/anki-note-builder.js';
 import {querySelectorNotNull} from '../../dom/query-selector.js';
 import {JapaneseUtil} from '../../language/sandbox/japanese-util.js';
@@ -266,7 +267,7 @@ export class AnkiTemplatesController {
                 allErrors.push(...errors);
             }
         } catch (e) {
-            allErrors.push(e instanceof Error ? e : new Error(`${e}`));
+            allErrors.push(toError(e));
         }
 
         /**
diff --git a/ext/js/pages/settings/backup-controller.js b/ext/js/pages/settings/backup-controller.js
index 2ae52925..457acc18 100644
--- a/ext/js/pages/settings/backup-controller.js
+++ b/ext/js/pages/settings/backup-controller.js
@@ -19,6 +19,7 @@
 import {Dexie} from '../../../lib/dexie.js';
 import {isObject, log} from '../../core.js';
 import {parseJson} from '../../core/json.js';
+import {toError} from '../../core/to-error.js';
 import {OptionsUtil} from '../../data/options-util.js';
 import {ArrayBufferUtil} from '../../data/sandbox/array-buffer-util.js';
 import {querySelectorNotNull} from '../../dom/query-selector.js';
@@ -498,7 +499,7 @@ export class BackupController {
         try {
             await this._importSettingsFile(file);
         } catch (error) {
-            this._showSettingsImportError(error instanceof Error ? error : new Error(`${error}`));
+            this._showSettingsImportError(toError(error));
         }
     }
 
diff --git a/ext/js/pages/settings/dictionary-import-controller.js b/ext/js/pages/settings/dictionary-import-controller.js
index eadfcb91..0c2fa7a5 100644
--- a/ext/js/pages/settings/dictionary-import-controller.js
+++ b/ext/js/pages/settings/dictionary-import-controller.js
@@ -18,6 +18,7 @@
 
 import {log} from '../../core.js';
 import {ExtensionError} from '../../core/extension-error.js';
+import {toError} from '../../core/to-error.js';
 import {DictionaryWorker} from '../../dictionary/dictionary-worker.js';
 import {querySelectorNotNull} from '../../dom/query-selector.js';
 import {yomitan} from '../../yomitan.js';
@@ -126,7 +127,7 @@ export class DictionaryImportController {
                 this._showErrors(errors);
             }
         } catch (error) {
-            this._showErrors([error instanceof Error ? error : new Error(`${error}`)]);
+            this._showErrors([toError(error)]);
         } finally {
             prevention.end();
             this._setModifying(false);
@@ -200,7 +201,7 @@ export class DictionaryImportController {
                 await this._importDictionary(files[i], importDetails, onProgress);
             }
         } catch (err) {
-            this._showErrors([err instanceof Error ? err : new Error(`${err}`)]);
+            this._showErrors([toError(err)]);
         } finally {
             prevention.end();
             for (const progress of progressContainers) { progress.hidden = true; }
diff --git a/ext/js/pages/settings/mecab-controller.js b/ext/js/pages/settings/mecab-controller.js
index 9c55c9a0..f57bc3c9 100644
--- a/ext/js/pages/settings/mecab-controller.js
+++ b/ext/js/pages/settings/mecab-controller.js
@@ -16,6 +16,7 @@
  * along with this program.  If not, see <https://www.gnu.org/licenses/>.
  */
 
+import {toError} from '../../core/to-error.js';
 import {querySelectorNotNull} from '../../dom/query-selector.js';
 import {yomitan} from '../../yomitan.js';
 
@@ -57,7 +58,7 @@ export class MecabController {
             await yomitan.api.testMecab();
             this._setStatus('Connection was successful', false);
         } catch (e) {
-            this._setStatus(e instanceof Error ? e.message : `${e}`, true);
+            this._setStatus(toError(e).message, true);
         } finally {
             this._testActive = false;
             /** @type {HTMLButtonElement} */ (this._testButton).disabled = false;
diff --git a/ext/js/pages/settings/permissions-origin-controller.js b/ext/js/pages/settings/permissions-origin-controller.js
index 3a9db602..73f06a56 100644
--- a/ext/js/pages/settings/permissions-origin-controller.js
+++ b/ext/js/pages/settings/permissions-origin-controller.js
@@ -17,6 +17,7 @@
  */
 
 import {EventListenerCollection} from '../../core.js';
+import {toError} from '../../core/to-error.js';
 import {querySelectorNotNull} from '../../dom/query-selector.js';
 
 export class PermissionsOriginController {
@@ -155,7 +156,7 @@ export class PermissionsOriginController {
         } catch (e) {
             const errorContainer = /** @type {HTMLElement} */ (this._errorContainer);
             errorContainer.hidden = false;
-            errorContainer.textContent = e instanceof Error ? e.message : `${e}`;
+            errorContainer.textContent = toError(e).message;
         }
         if (!added) { return false; }
         await this._updatePermissions();
diff --git a/ext/js/pages/settings/recommended-permissions-controller.js b/ext/js/pages/settings/recommended-permissions-controller.js
index a870de50..0500759e 100644
--- a/ext/js/pages/settings/recommended-permissions-controller.js
+++ b/ext/js/pages/settings/recommended-permissions-controller.js
@@ -17,6 +17,7 @@
  */
 
 import {EventListenerCollection} from '../../core.js';
+import {toError} from '../../core/to-error.js';
 
 export class RecommendedPermissionsController {
     /**
@@ -92,7 +93,7 @@ export class RecommendedPermissionsController {
         } catch (e) {
             if (this._errorContainer !== null) {
                 this._errorContainer.hidden = false;
-                this._errorContainer.textContent = e instanceof Error ? e.message : `${e}`;
+                this._errorContainer.textContent = toError(e).message;
             }
         }
         if (!added) { return false; }