fix: resolve all TypeScript strict null check errors

- Add proper eslint-disable comment for unavoidable 'any' at module boundary
- Fix nitro plugin to handle undefined config properly
- Add non-null assertions in test files after existence checks
- All 251 tests pass with zero TypeScript errors

This completes the module-builder migration with full type safety.

Authored by: Aaron Lippold<lippold@gmail.com>

Author: aaronlippold

src/module.ts

@@ -1,4 +1,3 @@
-import type { RuntimeConfig } from './runtime/types'
 import { fileURLToPath } from 'node:url'
 import { addPlugin, addServerPlugin, createResolver, defineNuxtModule } from '@nuxt/kit'
 
@@ -220,6 +219,8 @@ export default defineNuxtModule<ModuleOptions>({
     nuxt.options.css.push(resolver.resolve('./runtime/superscript.css'))
 
     // Pass module options to runtime
-    nuxt.options.runtimeConfig.public.smartscript = options as unknown as RuntimeConfig
+    // The options are merged with defaults by Nuxt, so all required fields are present
+    // eslint-disable-next-line ts/no-explicit-any
+    nuxt.options.runtimeConfig.public.smartscript = options as any
   },
 })

src/runtime/nitro/plugin.ts

@@ -16,10 +16,10 @@ export default <NitroAppPlugin> function (nitro) {
   // @ts-expect-error - render:html hook exists but not typed in nitropack
   nitro.hooks.hook('render:html', (html: Record<string, string[]>, { event }: { event: { context: { $config?: { public?: { smartscript?: SuperscriptConfig } } } } }) => {
     // Get configuration from runtime config
-    const config = event.context.$config?.public?.smartscript || {}
+    const config = event.context.$config?.public?.smartscript
 
-    // Skip if SSR processing is disabled
-    if (config.ssr === false) {
+    // Skip if no config or SSR processing is disabled
+    if (!config || config.ssr === false) {
       logger.debug('[Nitro] SSR processing disabled via config')
       return
     }

test/integration/element-positioning.test.ts

@@ -40,8 +40,8 @@ describe('element Positioning Integration', () => {
       expect(regElements.length).toBe(1)
 
       // Verify they are SPAN elements
-      expect(tmElements[0].tagName).toBe('SPAN')
-      expect(regElements[0].tagName).toBe('SPAN')
+      expect(tmElements[0]!.tagName).toBe('SPAN')
+      expect(regElements[0]!.tagName).toBe('SPAN')
     })
 
     it('should apply CSS variables to positioned elements', () => {

test/unit/dom.test.ts

@@ -114,7 +114,7 @@ describe('dOM Output: Actual Element Creation', () => {
       div.appendChild(fragment)
 
       expect(div.childNodes).toHaveLength(2)
-      expect(div.childNodes[0].textContent).toBe('MITRE')
+      expect(div.childNodes[0]!.textContent).toBe('MITRE')
 
       const sup = div.childNodes[1] as HTMLElement
       expect(sup.tagName).toBe('SPAN') // TM uses SPAN for positioning
@@ -133,7 +133,7 @@ describe('dOM Output: Actual Element Creation', () => {
       div.appendChild(fragment)
 
       expect(div.childNodes).toHaveLength(2)
-      expect(div.childNodes[0].textContent).toBe('1')
+      expect(div.childNodes[0]!.textContent).toBe('1')
 
       const sup = div.childNodes[1] as HTMLElement
       expect(sup.tagName).toBe('SUP')
@@ -153,14 +153,14 @@ describe('dOM Output: Actual Element Creation', () => {
       div.appendChild(fragment)
 
       expect(div.childNodes).toHaveLength(3)
-      expect(div.childNodes[0].textContent).toBe('H')
+      expect(div.childNodes[0]!.textContent).toBe('H')
 
       const sub = div.childNodes[1] as HTMLElement
       expect(sub.tagName).toBe('SUB')
       expect(sub.className).toBe('ss-sub')
       expect(sub.textContent).toBe('2')
 
-      expect(div.childNodes[2].textContent).toBe('O')
+      expect(div.childNodes[2]!.textContent).toBe('O')
     })
 
     it('should create fragment with mixed super and subscripts', () => {
@@ -201,8 +201,8 @@ describe('dOM Output: Actual Element Creation', () => {
       // Should have text "MITRE" and trademark "™" as SPAN (hybrid approach)
       const tmElements = div.querySelectorAll('span.ss-tm')
       expect(tmElements).toHaveLength(1)
-      expect(tmElements[0].className).toBe('ss-sup ss-tm')
-      expect(tmElements[0].textContent).toBe('™')
+      expect(tmElements[0]!.className).toBe('ss-sup ss-tm')
+      expect(tmElements[0]!.textContent).toBe('™')
     })
 
     it('should process ordinal numbers correctly', () => {
@@ -214,8 +214,8 @@ describe('dOM Output: Actual Element Creation', () => {
       // Should have "1" as text and "st" as superscript
       const supElements = div.querySelectorAll('sup.ss-sup')
       expect(supElements).toHaveLength(1)
-      expect(supElements[0].className).toBe('ss-sup ss-ordinal')
-      expect(supElements[0].textContent).toBe('st')
+      expect(supElements[0]!.className).toBe('ss-sup ss-ordinal')
+      expect(supElements[0]!.textContent).toBe('st')
     })
 
     it('should process chemical formulas correctly', () => {
@@ -227,7 +227,7 @@ describe('dOM Output: Actual Element Creation', () => {
       // Should have H, subscript 2, and O
       const subElements = div.querySelectorAll('sub.ss-sub')
       expect(subElements).toHaveLength(1)
-      expect(subElements[0].textContent).toBe('2')
+      expect(subElements[0]!.textContent).toBe('2')
     })
 
     it('should process math notation correctly', () => {
@@ -239,7 +239,7 @@ describe('dOM Output: Actual Element Creation', () => {
       // Should have superscript 2
       const supElements = div.querySelectorAll('sup.ss-sup')
       expect(supElements).toHaveLength(1)
-      expect(supElements[0].textContent).toBe('2')
+      expect(supElements[0]!.textContent).toBe('2')
     })
 
     it('should process copyright symbol correctly', () => {

test/unit/math-notation.test.ts

@@ -161,34 +161,34 @@ describe('mathematical Notation Support', () => {
       const result = processMatch('x_n')
       expect(result.modified).toBe(true)
       expect(result.parts).toHaveLength(2)
-      expect(result.parts[0].type).toBe('text')
-      expect(result.parts[0].content).toBe('x')
-      expect(result.parts[1].type).toBe('sub')
-      expect(result.parts[1].content).toBe('n')
+      expect(result.parts[0]!.type).toBe('text')
+      expect(result.parts[0]!.content).toBe('x')
+      expect(result.parts[1]!.type).toBe('sub')
+      expect(result.parts[1]!.content).toBe('n')
     })
 
     it('should correctly process single-letter superscripts', () => {
       const result = processMatch('x^n')
       expect(result.modified).toBe(true)
       expect(result.parts).toHaveLength(2)
-      expect(result.parts[0].type).toBe('text')
-      expect(result.parts[0].content).toBe('x')
-      expect(result.parts[1].type).toBe('super')
-      expect(result.parts[1].content).toBe('n')
+      expect(result.parts[0]!.type).toBe('text')
+      expect(result.parts[0]!.content).toBe('x')
+      expect(result.parts[1]!.type).toBe('super')
+      expect(result.parts[1]!.content).toBe('n')
     })
 
     it('should correctly extract content from braced expressions', () => {
       const result1 = processMatch('x_{n+1}')
       expect(result1.modified).toBe(true)
       expect(result1.parts).toHaveLength(2)
-      expect(result1.parts[0].content).toBe('x')
-      expect(result1.parts[1].content).toBe('n+1') // Braces removed
+      expect(result1.parts[0]!.content).toBe('x')
+      expect(result1.parts[1]!.content).toBe('n+1') // Braces removed
 
       const result2 = processMatch('x^{2n}')
       expect(result2.modified).toBe(true)
       expect(result2.parts).toHaveLength(2)
-      expect(result2.parts[0].content).toBe('x')
-      expect(result2.parts[1].content).toBe('2n') // Braces removed
+      expect(result2.parts[0]!.content).toBe('x')
+      expect(result2.parts[1]!.content).toBe('2n') // Braces removed
     })
 
     it('should handle nested braces in math', () => {

test/unit/processor.test.ts

@@ -205,7 +205,7 @@ describe('text Processing', () => {
       // Unicode input
       const unicodeResult = processMatch('™')
       expect(unicodeResult.modified).toBe(true)
-      expect(unicodeResult.parts[0].content).toBe('™')
+      expect(unicodeResult.parts[0]!.content).toBe('™')
 
       // Mixed case that shouldn't match
       const noMatch = processMatch('random text')

test/unit/regression/headers-bug.test.ts

@@ -51,8 +51,8 @@ describe('hTML Headers Bug Fix', () => {
       const result = processText(text, combinedPattern)
       // Should return as plain text, no transformations
       expect(result).toHaveLength(1)
-      expect(result[0].type).toBe('text')
-      expect(result[0].content).toBe(text)
+      expect(result[0]!.type).toBe('text')
+      expect(result[0]!.content).toBe(text)
     })
   })
 

test/unit/regression/water.test.ts

@@ -44,8 +44,8 @@ describe('water and Headers Test', () => {
       const result = processText(text, combinedPattern)
       // Should be plain text, no transformations
       expect(result).toHaveLength(1)
-      expect(result[0].type).toBe('text')
-      expect(result[0].content).toBe(text)
+      expect(result[0]!.type).toBe('text')
+      expect(result[0]!.content).toBe(text)
     })
   })
 
@@ -69,8 +69,8 @@ describe('water and Headers Test', () => {
     // Should have subscripts for both 2 and 4
     const subscripts = result.filter((p) => p.type === 'sub')
     expect(subscripts.length).toBe(2)
-    expect(subscripts[0].content).toBe('2')
-    expect(subscripts[1].content).toBe('4')
+    expect(subscripts[0]!.content).toBe('2')
+    expect(subscripts[1]!.content).toBe('4')
   })
 
   it('should NOT transform H7 or higher', () => {

test/unit/ssr.test.ts

@@ -185,12 +185,12 @@ describe('sSR with jsdom', () => {
       const divs = document.querySelectorAll('div')
 
       // First div with data-no-superscript should remain unchanged
-      expect(divs[0].innerHTML).toBe('Product(TM) H2O')
+      expect(divs[0]!.innerHTML).toBe('Product(TM) H2O')
 
       // Second div should be transformed
-      expect(divs[1].innerHTML).toContain('<span class="ss-sup ss-tm" aria-label="trademark">™</span>')
-      expect(divs[1].innerHTML).toContain('H<sub class="ss-sub"')
-      expect(divs[1].innerHTML).toContain('>2</sub>O')
+      expect(divs[1]!.innerHTML).toContain('<span class="ss-sup ss-tm" aria-label="trademark">™</span>')
+      expect(divs[1]!.innerHTML).toContain('H<sub class="ss-sub"')
+      expect(divs[1]!.innerHTML).toContain('>2</sub>O')
     })
 
     it('should not transform nested exclusions', () => {

test/unit/transformations.test.ts

@@ -238,8 +238,8 @@ describe('transformation Configuration', () => {
 
       // Everything should remain as plain text
       expect(parts).toHaveLength(1)
-      expect(parts[0].type).toBe('text')
-      expect(parts[0].content).toBe(text)
+      expect(parts[0]!.type).toBe('text')
+      expect(parts[0]!.content).toBe(text)
     })
   })