fix(aliases): Fix wikilink resolution for aliases

With markdownLinkResolution: "shortest", aka "+/- how Obsidian does it"
and given pages A and nested/B which has an alias Z, if you try to link
from A using [[Z]] it wouldn't work and get 404.

This is caused by alias slugs (nested/Z in this case, emitted by
AliasRedirects) not being present in the `allSlugs` list which is used
by the link transformer.

The fix is to compute the alias slugs in the frontmatter transformer
and add them to `allSlugs` there.
Also we store them in file data to avoid recomputing them when emitting
alias redirect pages.

Fixes #904

Note: given how currently the markdown/html transformers are ordered
this doesn't really work.

Given pages A and nested/B which has an alias Z, here's the order which
currently happens:

md-transformers(A) => html-transformers(A) =>
md-transformers(B) => html-transformers(B)

Since the nested/Z slug will get added when md-transformers(B) are run,
but the slugs are used by html-transformers(A) when resolving it's
links - the link [[Z]] in A will still 404

A fix for this is to split the parser into two stages - first apply the
md-transformers to all files, and only then apply html-transformers to
all files.

I did just that in a different commit, which is needed for this one to
work correctly.

quartz/plugins/emitters/aliases.ts

@@ -1,8 +1,8 @@
-import { FilePath, FullSlug, joinSegments, resolveRelative, simplifySlug } from "../../util/path"
+import { FilePath, joinSegments, resolveRelative, simplifySlug } from "../../util/path"
 import { QuartzEmitterPlugin } from "../types"
-import path from "path"
 import { write } from "./helpers"
 import DepGraph from "../../depgraph"
+import { getAliasSlugs } from "../transformers/frontmatter"
 
 export const AliasRedirects: QuartzEmitterPlugin = () => ({
   name: "AliasRedirects",
@@ -14,20 +14,7 @@ export const AliasRedirects: QuartzEmitterPlugin = () => ({
 
     const { argv } = ctx
     for (const [_tree, file] of content) {
-      const dir = path.posix.relative(argv.directory, path.dirname(file.data.filePath!))
-      const aliases = file.data.frontmatter?.aliases ?? []
-      const slugs = aliases.map((alias) => path.posix.join(dir, alias) as FullSlug)
-      const permalink = file.data.frontmatter?.permalink
-      if (typeof permalink === "string") {
-        slugs.push(permalink as FullSlug)
-      }
-
-      for (let slug of slugs) {
-        // fix any slugs that have trailing slash
-        if (slug.endsWith("/")) {
-          slug = joinSegments(slug, "index") as FullSlug
-        }
-
+      for (const slug of getAliasSlugs(file.data.frontmatter?.aliases ?? [], argv, file)) {
         graph.addEdge(file.data.filePath!, joinSegments(argv.output, slug + ".html") as FilePath)
       }
     }
@@ -40,20 +27,8 @@ export const AliasRedirects: QuartzEmitterPlugin = () => ({
 
     for (const [_tree, file] of content) {
       const ogSlug = simplifySlug(file.data.slug!)
-      const dir = path.posix.relative(argv.directory, path.dirname(file.data.filePath!))
-      const aliases = file.data.frontmatter?.aliases ?? []
-      const slugs: FullSlug[] = aliases.map((alias) => path.posix.join(dir, alias) as FullSlug)
-      const permalink = file.data.frontmatter?.permalink
-      if (typeof permalink === "string") {
-        slugs.push(permalink as FullSlug)
-      }
-
-      for (let slug of slugs) {
-        // fix any slugs that have trailing slash
-        if (slug.endsWith("/")) {
-          slug = joinSegments(slug, "index") as FullSlug
-        }
 
+      for (const slug of file.data.aliases ?? []) {
         const redirUrl = resolveRelative(slug, file.data.slug!)
         const fp = await write({
           ctx,

quartz/plugins/transformers/frontmatter.ts

@@ -3,9 +3,12 @@ import remarkFrontmatter from "remark-frontmatter"
 import { QuartzTransformerPlugin } from "../types"
 import yaml from "js-yaml"
 import toml from "toml"
-import { slugTag } from "../../util/path"
+import { FilePath, FullSlug, joinSegments, slugifyFilePath, slugTag } from "../../util/path"
 import { QuartzPluginData } from "../vfile"
 import { i18n } from "../../i18n"
+import { Argv } from "../../util/ctx"
+import { VFile } from "vfile"
+import path from "path"
 
 export interface Options {
   delimiters: string | [string, string]
@@ -40,11 +43,26 @@ function coerceToArray(input: string | string[]): string[] | undefined {
     .map((tag: string | number) => tag.toString())
 }
 
+export function getAliasSlugs(aliases: string[], argv: Argv, file: VFile): FullSlug[] {
+  const dir = path.posix.relative(argv.directory, path.dirname(file.data.filePath!))
+  const slugs: FullSlug[] = aliases.map(
+    (alias) => path.posix.join(dir, slugifyFilePath(alias as FilePath)) as FullSlug,
+  )
+  const permalink = file.data.frontmatter?.permalink
+  if (typeof permalink === "string") {
+    slugs.push(permalink as FullSlug)
+  }
+  // fix any slugs that have trailing slash
+  return slugs.map((slug) =>
+    slug.endsWith("/") ? (joinSegments(slug, "index") as FullSlug) : slug,
+  )
+}
+
 export const FrontMatter: QuartzTransformerPlugin<Partial<Options>> = (userOpts) => {
   const opts = { ...defaultOptions, ...userOpts }
   return {
     name: "FrontMatter",
-    markdownPlugins({ cfg }) {
+    markdownPlugins({ cfg, allSlugs, argv }) {
       return [
         [remarkFrontmatter, ["yaml", "toml"]],
         () => {
@@ -67,7 +85,11 @@ export const FrontMatter: QuartzTransformerPlugin<Partial<Options>> = (userOpts)
             if (tags) data.tags = [...new Set(tags.map((tag: string) => slugTag(tag)))]
 
             const aliases = coerceToArray(coalesceAliases(data, ["aliases", "alias"]))
-            if (aliases) data.aliases = aliases
+            if (aliases) {
+              data.aliases = aliases // frontmatter
+              const slugs = (file.data.aliases = getAliasSlugs(aliases, argv, file))
+              allSlugs.push(...slugs)
+            }
             const cssclasses = coerceToArray(coalesceAliases(data, ["cssclasses", "cssclass"]))
             if (cssclasses) data.cssclasses = cssclasses
 
@@ -98,6 +120,7 @@ export const FrontMatter: QuartzTransformerPlugin<Partial<Options>> = (userOpts)
 
 declare module "vfile" {
   interface DataMap {
+    aliases: FullSlug[]
     frontmatter: { [key: string]: unknown } & {
       title: string
     } & Partial<{