|
1 | | -import type { HandlerEvent } from '@netlify/functions' |
| 1 | +import type { IncomingMessage, ServerResponse } from 'http' |
| 2 | + |
2 | 3 | import type { NextConfigComplete } from 'next/dist/server/config-shared.js' |
3 | 4 |
|
4 | | -export interface NetlifyVaryHeaderBuilder { |
| 5 | +type HeaderValue = number | string | string[] |
| 6 | + |
| 7 | +interface NetlifyVaryDirectives { |
5 | 8 | headers: string[] |
6 | 9 | languages: string[] |
7 | 10 | cookies: string[] |
8 | 11 | } |
9 | 12 |
|
10 | | -const generateNetlifyVaryHeaderValue = ({ headers, languages, cookies }: NetlifyVaryHeaderBuilder): string => { |
11 | | - let NetlifyVaryHeader = `` |
12 | | - if (headers && headers.length !== 0) { |
13 | | - NetlifyVaryHeader += `header=${headers.join(`|`)}` |
| 13 | +const generateNetlifyVaryDirectives = ({ |
| 14 | + headers, |
| 15 | + languages, |
| 16 | + cookies, |
| 17 | +}: NetlifyVaryDirectives): string[] => { |
| 18 | + const directives = [] |
| 19 | + if (headers.length !== 0) { |
| 20 | + directives.push(`header=${headers.join(`|`)}`) |
14 | 21 | } |
15 | | - if (languages && languages.length !== 0) { |
16 | | - if (NetlifyVaryHeader.length !== 0) { |
17 | | - NetlifyVaryHeader += `,` |
18 | | - } |
19 | | - NetlifyVaryHeader += `language=${languages.join(`|`)}` |
| 22 | + if (languages.length !== 0) { |
| 23 | + directives.push(`language=${languages.join(`|`)}`) |
20 | 24 | } |
21 | | - if (cookies && cookies.length !== 0) { |
22 | | - if (NetlifyVaryHeader.length !== 0) { |
23 | | - NetlifyVaryHeader += `,` |
24 | | - } |
25 | | - NetlifyVaryHeader += `cookie=${cookies.join(`|`)}` |
| 25 | + if (cookies.length !== 0) { |
| 26 | + directives.push(`cookie=${cookies.join(`|`)}`) |
26 | 27 | } |
27 | | - |
28 | | - return NetlifyVaryHeader |
| 28 | + return directives |
29 | 29 | } |
30 | 30 |
|
31 | | -const getDirectives = (headerValue: string): string[] => headerValue.split(',').map((directive) => directive.trim()) |
32 | | - |
33 | | -const removeSMaxAgeAndStaleWhileRevalidate = (headerValue: string): string => |
34 | | - getDirectives(headerValue) |
35 | | - .filter((directive) => { |
36 | | - if (directive.startsWith('s-maxage')) { |
37 | | - return false |
38 | | - } |
39 | | - if (directive.startsWith('stale-while-revalidate')) { |
40 | | - return false |
41 | | - } |
42 | | - return true |
43 | | - }) |
44 | | - .join(`,`) |
45 | | - |
46 | | -export const handleVary = (headers: Record<string, string>, event: HandlerEvent, nextConfig: NextConfigComplete) => { |
47 | | - const netlifyVaryBuilder: NetlifyVaryHeaderBuilder = { |
| 31 | +/** |
| 32 | + * Parse a header value into an array of directives |
| 33 | + */ |
| 34 | +const getDirectives = (headerValue: HeaderValue): string[] => { |
| 35 | + const directives = Array.isArray(headerValue) ? headerValue : String(headerValue).split(',') |
| 36 | + return directives.map((directive) => directive.trim()) |
| 37 | +} |
| 38 | +/** |
| 39 | + * Ensure the Netlify CDN varies on things that Next.js varies on, |
| 40 | + * e.g. i18n, preview mode, etc. |
| 41 | + */ |
| 42 | +export const setVaryHeaders = ( |
| 43 | + res: ServerResponse, |
| 44 | + req: IncomingMessage, |
| 45 | + { basePath, i18n }: NextConfigComplete, |
| 46 | +) => { |
| 47 | + const netlifyVaryDirectives: NetlifyVaryDirectives = { |
48 | 48 | headers: [], |
49 | 49 | languages: [], |
50 | 50 | cookies: ['__prerender_bypass', '__next_preview_data'], |
51 | 51 | } |
52 | 52 |
|
53 | | - if (headers.vary.length !== 0) { |
54 | | - netlifyVaryBuilder.headers.push(...getDirectives(headers.vary)) |
| 53 | + const vary = res.getHeader('vary') |
| 54 | + if (vary !== undefined) { |
| 55 | + netlifyVaryDirectives.headers.push(...getDirectives(vary)) |
55 | 56 | } |
56 | 57 |
|
57 | | - const autoDetectedLocales = getAutoDetectedLocales(nextConfig) |
58 | | - |
59 | | - if (autoDetectedLocales.length > 1) { |
60 | | - const logicalPath = |
61 | | - nextConfig.basePath && event.path.startsWith(nextConfig.basePath) |
62 | | - ? event.path.slice(nextConfig.basePath.length) |
63 | | - : event.path |
| 58 | + const path = new URL(req.url ?? '/', `http://${req.headers.host}`).pathname |
| 59 | + const locales = i18n && i18n.localeDetection !== false ? i18n.locales : [] |
64 | 60 |
|
| 61 | + if (locales.length > 1) { |
| 62 | + const logicalPath = basePath && path.startsWith(basePath) ? path.slice(basePath.length) : path |
65 | 63 | if (logicalPath === `/`) { |
66 | | - netlifyVaryBuilder.languages.push(...autoDetectedLocales) |
67 | | - netlifyVaryBuilder.cookies.push(`NEXT_LOCALE`) |
| 64 | + netlifyVaryDirectives.languages.push(...locales) |
| 65 | + netlifyVaryDirectives.cookies.push(`NEXT_LOCALE`) |
68 | 66 | } |
69 | 67 | } |
70 | 68 |
|
71 | | - const NetlifyVaryHeader = generateNetlifyVaryHeaderValue(netlifyVaryBuilder) |
72 | | - if (NetlifyVaryHeader.length !== 0) { |
73 | | - headers[`netlify-vary`] = NetlifyVaryHeader |
74 | | - } |
75 | | -} |
76 | | - |
77 | | -export const handleCacheControl = (headers: Record<string, string>) => { |
78 | | - if (headers['cache-control'] && !headers['cdn-cache-control'] && !headers['netlify-cdn-cache-control']) { |
79 | | - headers['netlify-cdn-cache-control'] = headers['cache-control'] |
80 | | - |
81 | | - const filteredCacheControlDirectives = removeSMaxAgeAndStaleWhileRevalidate(headers['cache-control']) |
82 | | - |
83 | | - // use default cache-control if no directives are left |
84 | | - headers['cache-control'] = |
85 | | - filteredCacheControlDirectives.length === 0 |
86 | | - ? 'public, max-age=0, must-revalidate' |
87 | | - : filteredCacheControlDirectives |
88 | | - } |
| 69 | + res.setHeader(`netlify-vary`, generateNetlifyVaryDirectives(netlifyVaryDirectives)) |
89 | 70 | } |
90 | 71 |
|
91 | | -export const getAutoDetectedLocales = (config: NextConfigComplete): Array<string> => { |
92 | | - if (config.i18n && config.i18n.localeDetection !== false && config.i18n.locales.length > 1) { |
93 | | - return config.i18n.locales |
| 72 | +/** |
| 73 | + * Ensure stale-while-revalidate and s-maxage don't leak to the client, but |
| 74 | + * assume the user knows what they are doing if CDN cache controls are set |
| 75 | + */ |
| 76 | +export const setCacheControlHeaders = (res: ServerResponse) => { |
| 77 | + const cacheControl = res.getHeader('cache-control') |
| 78 | + if ( |
| 79 | + cacheControl !== undefined && |
| 80 | + !res.hasHeader('cdn-cache-control') && |
| 81 | + !res.hasHeader('netlify-cdn-cache-control') |
| 82 | + ) { |
| 83 | + const directives = getDirectives(cacheControl).filter( |
| 84 | + (directive) => |
| 85 | + !directive.startsWith('s-maxage') && !directive.startsWith('stale-while-revalidate'), |
| 86 | + ) |
| 87 | + |
| 88 | + res.setHeader('netlify-cdn-cache-control', cacheControl) |
| 89 | + res.setHeader( |
| 90 | + 'cache-control', |
| 91 | + directives.length === 0 ? 'public, max-age=0, must-revalidate' : directives, |
| 92 | + ) |
94 | 93 | } |
95 | | - |
96 | | - return [] |
97 | 94 | } |
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