feat(dev): introduce strict null checks (#99)

* feat(dev): introduce strict null checks * feat(dev): introduce strict null checks * fix: comply with strict-null-checks
joplin · Sep 18, 2024 · 4a0b645 · 4a0b645
1 parent 7a643ff
commit 4a0b645
Show file tree

Hide file tree

Showing 11 changed files with 89 additions and 26 deletions.
diff --git a/src/index.ts b/src/index.ts
@@ -98,12 +98,12 @@ joplin.plugins.register({
         }
 
         const getTemplateAndPerformAction = async (action: TemplateAction) => {
-            const template: Note = JSON.parse(await getUserTemplateSelection());
+            const template: Note = JSON.parse(await getUserTemplateSelection() || "null");
             await performActionWithParsedTemplate(action, template);
         }
 
         const getNotebookDefaultTemplatesDisplayData = async (settings: DefaultTemplatesConfigSetting): Promise<NotebookDefaultTemplatesDisplayData[]> => {
-            const getDisplayDataForNotebook = async (notebookId: string, defaultTemplateNoteId: string, defaultTemplateTodoId: string): Promise<NotebookDefaultTemplatesDisplayData | null> => {
+            const getDisplayDataForNotebook = async (notebookId: string, defaultTemplateNoteId: string | null, defaultTemplateTodoId: string | null): Promise<NotebookDefaultTemplatesDisplayData | null> => {
                 const promiseGroup = new PromiseGroup();
                 promiseGroup.set("notebook", getFolderFromId(notebookId));
                 promiseGroup.set("noteTemplate", getTemplateFromId(defaultTemplateNoteId));
@@ -196,7 +196,7 @@ joplin.plugins.register({
             name: "setDefaultTemplateForNotebook",
             label: "Set default template for notebook",
             execute: async () => {
-                const folder: Folder | null = JSON.parse(await getUserFolderSelection());
+                const folder: Folder | null = JSON.parse(await getUserFolderSelection() || "null");
                 if (folder === null) return;
 
                 const templateId = await getUserTemplateSelection("id", `Default template for "${folder.title}":`);
@@ -214,7 +214,7 @@ joplin.plugins.register({
             name: "clearDefaultTemplatesForNotebook",
             label: "Clear default templates for notebook",
             execute: async () => {
-                const folder: Folder | null = JSON.parse(await getUserFolderSelection());
+                const folder: Folder | null = JSON.parse(await getUserFolderSelection() || "null");
                 if (folder === null) return;
 
                 await clearDefaultTemplates(folder.id);

diff --git a/src/legacyTemplates.ts b/src/legacyTemplates.ts
@@ -25,8 +25,8 @@ const getTemplatesTag = async (): Promise<string> => {
 export const loadLegacyTemplates = async (dateAndTimeUtils: DateAndTimeUtils, profileDir: string): Promise<void> => {
     const fs = joplin.require("fs-extra");
 
-    let folderId = null;
-    let templatesTagId = null;
+    let folderId: string | null = null;
+    let templatesTagId: string | null = null;
 
     const templatesDir = `${profileDir}/templates`;
 

diff --git a/src/parser.ts b/src/parser.ts
@@ -4,6 +4,7 @@ import { Logger } from "./logger";
 import { DateAndTimeUtils } from "./utils/dateAndTime";
 import { doesFolderExist } from "./utils/folders";
 import { Note } from "./utils/templates";
+import { notEmpty } from "./utils/typescript";
 import { getVariableFromDefinition } from "./variables/parser";
 import { CustomVariable } from "./variables/types/base";
 import { setTemplateVariablesView } from "./views/templateVariables";
@@ -23,6 +24,13 @@ export interface NewNote {
     todo_due: number | null;
 }
 
+interface NoteMetadata {
+    title: string;
+    tags: string[];
+    folder: string | null;
+    todo_due: number | null;
+}
+
 const NOTE_TITLE_VARIABLE_NAME = "template_title";
 const NOTE_TAGS_VARIABLE_NAME = "template_tags";
 const NOTE_FOLDER_VARIABLE_NAME = "template_notebook";
@@ -129,8 +137,8 @@ export class Parser {
         return res;
     }
 
-    private async getNoteMetadata(parsedSpecialVariables: Record<string, string>) {
-        const meta = {
+    private async getNoteMetadata(parsedSpecialVariables: Record<string, string>): Promise<NoteMetadata> {
+        const meta: NoteMetadata = {
             title: parsedSpecialVariables.fallback_note_title,
             tags: [],
             folder: null,
@@ -183,7 +191,7 @@ export class Parser {
                 } else {
                     return null;
                 }
-            }).filter(val => !!val);
+            }).filter(notEmpty);
 
             if (!allMatchesAfterFirstMatch.length) {
                 return null;
@@ -229,7 +237,7 @@ export class Parser {
         return `${variableDefinitionsBlock}${templateContentBlock}`;
     }
 
-    public async parseTemplate(template: Note | null): Promise<NewNote> {
+    public async parseTemplate(template: Note | null): Promise<NewNote | null> {
         if (!template) {
             return null;
         }

diff --git a/src/utils/dateAndTime.ts b/src/utils/dateAndTime.ts
@@ -40,14 +40,14 @@ export class DateAndTimeUtils {
         return `${this.dateFormat} ${this.timeFormat}`;
     }
 
-    public formatMsToLocal(ms: number, format: string = null): string {
+    public formatMsToLocal(ms: number, format: string | null = null): string {
         if (!format) {
             format = this.getDateTimeFormat();
         }
         return moment(ms).format(format);
     }
 
-    public formatLocalToJoplinCompatibleUnixTime(input: string, format: string = null): number {
+    public formatLocalToJoplinCompatibleUnixTime(input: string, format: string | null = null): number {
         if (!format) {
             format = this.getDateTimeFormat();
         }
@@ -60,7 +60,7 @@ export class DateAndTimeUtils {
         return date.unix() * 1000;
     }
 
-    public getCurrentTime(format: string = null): string {
+    public getCurrentTime(format: string | null = null): string {
         return this.formatMsToLocal(new Date().getTime(), format);
     }
 

diff --git a/src/utils/typescript.ts b/src/utils/typescript.ts
@@ -0,0 +1,6 @@
+/** Can be used to filter non empty values from a collection while adhering to typescript
+ * strict null checks.
+ */
+export function notEmpty<T>(value: T | null | undefined): value is T {
+    return value !== null && value !== undefined;
+}
diff --git a/src/variables/parser.ts b/src/variables/parser.ts
@@ -32,4 +32,8 @@ export const getVariableFromDefinition = (name: string, definition: unknown): Cu
             throw err;
         }
     }
+
+    // This ideally should never happen. "InvalidCustomVariable" accepts
+    // all definitions.
+    throw Error("No valid definition for variable: " + name);
 }
diff --git a/src/variables/types/base.ts b/src/variables/types/base.ts
@@ -40,7 +40,7 @@ export class CustomVariable {
     static createFromDefinition(name: string, definition: unknown): CustomVariable {
         if (typeof definition === "string" && definition.trim() === this.definitionName) {
             return new this(name, name);
-        } else if (typeof definition === "object") {
+        } else if (typeof definition === "object" && definition !== null) {
             if ("type" in definition) {
                 const variableType = definition["type"];
                 if (typeof variableType === "string" && variableType.trim() === this.definitionName) {

diff --git a/src/variables/types/enum.ts b/src/variables/types/enum.ts
@@ -35,7 +35,7 @@ export class EnumCustomVariable extends CustomVariable {
         if (typeof definition === "string") {
             const options = this.getOptionsFromType(definition);
             return new this(name, name, options);
-        } else if (typeof definition === "object") {
+        } else if (typeof definition === "object" && definition !== null) {
             if ("type" in definition) {
                 const variableType = definition["type"];
                 if (typeof variableType === "string") {