# core/validators/build.validator.ts

> 32 lines of code and 12 definitions.

Tree: Bane's Lab Build Scripts
Language: typescript
Layer: processing
Canonical: https://banes-lab.com/anatomy/build-scripts#file-build-scripts-core-validators-build-validator-ts
Source text: https://banes-lab.com/source/build-scripts/core/validators/build.validator.ts.txt

Listed in [core/validators](https://banes-lab.com/api/source/build-scripts/core/validators.md), after [core/validators/asset.validator.ts](https://banes-lab.com/source/build-scripts/core/validators/asset.validator.ts.md) and before [core/validators/catalog.grammar.validator.ts](https://banes-lab.com/source/build-scripts/core/validators/catalog.grammar.validator.ts.md).

## Definitions

- `checkFile` (lexical_declaration, line 13, exported)
- `checkPageBytes` (lexical_declaration, line 18, exported)
- `checkPageHeadings` (lexical_declaration, line 35, exported)
- `isServedUrl` (lexical_declaration, line 9, exported)
- `text` (lexical_declaration, line 14, exported)
- `bytes` (lexical_declaration, line 19, exported)
- `HEADING_OPEN` (lexical_declaration, line 23)
- `HEADING_ENDS` (lexical_declaration, line 24)
- `headingsIn` (lexical_declaration, line 26)
- `at` (lexical_declaration, line 27)
- `next` (lexical_declaration, line 31)
- `count` (lexical_declaration, line 36, exported)

## Contained in

- [core/validators](https://banes-lab.com/anatomy/build-scripts/folder-build-scripts-core-validators.md)

## Uses

- [configuration/strings/validation.strings.ts](https://banes-lab.com/source/build-scripts/configuration/strings/validation.strings.ts.md)
- [core/converters/reference.converter.ts](https://banes-lab.com/source/build-scripts/core/converters/reference.converter.ts.md)
- [core/loaders/build.loader.ts](https://banes-lab.com/source/build-scripts/core/loaders/build.loader.ts.md)
- [core/resolvers/catalog.resolver.ts](https://banes-lab.com/source/build-scripts/core/resolvers/catalog.resolver.ts.md)

## Used by

- [core/coordinators/validation.coordinator.ts](https://banes-lab.com/source/build-scripts/core/coordinators/validation.coordinator.ts.md)
- [core/validators/security.validator.ts](https://banes-lab.com/source/build-scripts/core/validators/security.validator.ts.md)
- [core/validators/source.page.validator.ts](https://banes-lab.com/source/build-scripts/core/validators/source.page.validator.ts.md)

## Linked from

- [configuration/strings](https://banes-lab.com/anatomy/build-scripts/folder-build-scripts-configuration-strings.md)
- [core/converters](https://banes-lab.com/anatomy/build-scripts/folder-build-scripts-core-converters.md)
- [core/coordinators](https://banes-lab.com/anatomy/build-scripts/folder-build-scripts-core-coordinators.md)
- [core/loaders](https://banes-lab.com/anatomy/build-scripts/folder-build-scripts-core-loaders.md)
- [core/resolvers](https://banes-lab.com/anatomy/build-scripts/folder-build-scripts-core-resolvers.md)
- [core/validators](https://banes-lab.com/anatomy/build-scripts/folder-build-scripts-core-validators.md)

## Source

```typescript
import { MISSING_BUILD_FILE, oversizePage, pageHeadings } from "#configuration/strings/validation.strings";
import { fileOfAddress, localAddress } from "#core/resolvers/catalog.resolver";
import { Buffer } from "node:buffer";
import type { Finding } from "#types/validation.types";
import { PAGE_BYTE_BUDGET } from "#configuration/constants/site.constants";
import { SITE_URL } from "@banes-lab/web/core/assets/link.assets.ts";
import { readOrNull } from "#core/loaders/build.loader";

export const isServedUrl = function isServedUrl(url: string): boolean {
    return url.startsWith(SITE_URL) && readOrNull(fileOfAddress(localAddress(SITE_URL, url))) !== null;
};

export const checkFile = function checkFile(file: string, check: (text: string) => Finding[]): Finding[] {
    const text = readOrNull(file);
    return text === null ? [{ file, message: MISSING_BUILD_FILE }] : check(text);
};

export const checkPageBytes = function checkPageBytes(file: string, html: string): Finding[] {
    const bytes = Buffer.byteLength(html);
    return bytes > PAGE_BYTE_BUDGET ? [{ file, message: oversizePage(bytes, PAGE_BYTE_BUDGET) }] : [];
};

const HEADING_OPEN = "<h1";
const HEADING_ENDS: ReadonlySet<string> = new Set([">", " "]);

const headingsIn = function headingsIn(html: string, from = 0, count = 0): number {
    const at = html.indexOf(HEADING_OPEN, from);
    if (at === -1) {
        return count;
    }
    const next = at + HEADING_OPEN.length;
    return headingsIn(html, next, HEADING_ENDS.has(html.charAt(next)) ? count + 1 : count);
};

export const checkPageHeadings = function checkPageHeadings(file: string, html: string): Finding[] {
    const count = headingsIn(html);
    return count === 1 ? [] : [{ file, message: pageHeadings(count) }];
};
```