feat: Add {file, name, dir, ext} to classNameSlug resolution

packages/babel/__tests__/__snapshots__/babel.test.ts.snap

@@ -97,15 +97,15 @@ exports[`handles fn passed in as classNameSlug 1`] = `
 "import { styled } from '@linaria/react';
 export const Title = /*#__PURE__*/styled('h1')({
   name: \\"Title\\",
-  class: \\"t17gu1mi_42_Title\\"
+  class: \\"t17gu1mi_Title_t17gu1mi_Title__tests___app_index_js_index__js_app\\"
 });"
 `;
 
 exports[`handles fn passed in as classNameSlug 2`] = `
 
 CSS:
 
-.t17gu1mi_42_Title {
+.t17gu1mi_Title_t17gu1mi_Title__tests___app_index_js_index__js_app {
   font-size: 14px;
 }
 
@@ -389,6 +389,26 @@ Dependencies: NA
 
 `;
 
+exports[`removes fake replacement patterns in string classNameSlug 1`] = `
+"import { styled } from '@linaria/react';
+export const Title = /*#__PURE__*/styled('h1')({
+  name: \\"Title\\",
+  class: \\"__\\"
+});"
+`;
+
+exports[`removes fake replacement patterns in string classNameSlug 2`] = `
+
+CSS:
+
+.__ {
+  font-size: 14px;
+}
+
+Dependencies: NA
+
+`;
+
 exports[`replaces unknown expressions with CSS custom properties 1`] = `
 "import { styled } from '@linaria/react';
 export const Title = /*#__PURE__*/styled(\\"h1\\")({
@@ -552,15 +572,15 @@ exports[`uses string passed in as classNameSlug 1`] = `
 "import { styled } from '@linaria/react';
 export const Title = /*#__PURE__*/styled('h1')({
   name: \\"Title\\",
-  class: \\"testSlug\\"
+  class: \\"t17gu1mi_Title__tests___app_index_js_index__js_app\\"
 });"
 `;
 
 exports[`uses string passed in as classNameSlug 2`] = `
 
 CSS:
 
-.testSlug {
+.t17gu1mi_Title__tests___app_index_js_index__js_app {
   font-size: 14px;
 }
 

packages/babel/__tests__/babel.test.ts

@@ -43,7 +43,29 @@ it('uses string passed in as classNameSlug', async () => {
       font-size: 14px;
     \`;
 `,
-    { classNameSlug: 'testSlug' }
+    {
+      classNameSlug: ['hash', 'title', 'file', 'name', 'ext', 'dir']
+        .map((s) => `[${s}]`)
+        .join('_'),
+    }
+  );
+
+  expect(code).toMatchSnapshot();
+  expect(metadata).toMatchSnapshot();
+});
+
+it('removes fake replacement patterns in string classNameSlug', async () => {
+  const { code, metadata } = await transpile(
+    dedent`
+    import { styled } from '@linaria/react';
+
+    export const Title = styled('h1')\`
+      font-size: 14px;
+    \`;
+`,
+    {
+      classNameSlug: `[not]_[actual]_[replacements]`,
+    }
   );
 
   expect(code).toMatchSnapshot();
@@ -60,8 +82,17 @@ it('handles fn passed in as classNameSlug', async () => {
     \`;
 `,
     {
-      classNameSlug: (hash, title) => {
-        return `${hash}_${7 * 6}_${title}`;
+      classNameSlug: (hash, title, vars) => {
+        return [
+          hash,
+          title,
+          vars.hash,
+          vars.title,
+          vars.file,
+          vars.name,
+          vars.ext,
+          vars.dir,
+        ].join('_');
       },
     }
   );

packages/babel/src/types.ts

@@ -113,7 +113,20 @@ export type EvalRule = {
   action: Evaluator | 'ignore' | string;
 };
 
-type ClassNameFn = (hash: string, title: string) => string;
+export type ClassNameSlugVars = {
+  hash: string;
+  title: string;
+  file: string;
+  ext: string;
+  name: string;
+  dir: string;
+};
+
+type ClassNameFn = (
+  hash: string,
+  title: string,
+  args: ClassNameSlugVars
+) => string;
 
 export type StrictOptions = {
   classNameSlug?: string | ClassNameFn;

packages/babel/src/utils/isSlugVar.ts

@@ -0,0 +1,8 @@
+import { ClassNameSlugVars } from '../types';
+
+const isSlugVar = (
+  key: string,
+  slugVars: ClassNameSlugVars
+): key is keyof ClassNameSlugVars => key in slugVars;
+
+export default isSlugVar;

packages/babel/src/visitors/GenerateClassNames.ts

@@ -5,16 +5,17 @@
  * It saves that meta data as comment above the template, to be later used in templateProcessor.
  */
 
-import { basename, dirname, relative } from 'path';
+import { basename, dirname, relative, extname, sep } from 'path';
 import type { ObjectProperty, TaggedTemplateExpression } from '@babel/types';
 import type { NodePath } from '@babel/traverse';
 import { debug } from '@linaria/logger';
-import type { State, StrictOptions } from '../types';
+import type { ClassNameSlugVars, State, StrictOptions } from '../types';
 import toValidCSSIdentifier from '../utils/toValidCSSIdentifier';
 import slugify from '../utils/slugify';
 import getLinariaComment from '../utils/getLinariaComment';
 import isStyledOrCss from '../utils/isStyledOrCss';
 import { Core } from '../babel';
+import isSlugVar from '../utils/isSlugVar';
 
 export default function GenerateClassNames(
   babel: Core,
@@ -106,6 +107,19 @@ export default function GenerateClassNames(
       )}`
     );
 
+  // Collect some useful replacement patterns from the filename
+  // Available variables for the square brackets used in `classNameSlug` options
+  const file = relative(process.cwd(), state.file.opts.filename).slice(1);
+  const ext = extname(file);
+  const slugVars: ClassNameSlugVars = {
+    hash: slug,
+    title: displayName,
+    file,
+    ext,
+    name: basename(file, ext),
+    dir: dirname(file).split(sep).pop() as string,
+  };
+
   let className = predefinedClassName
     ? predefinedClassName
     : options.displayName
@@ -116,7 +130,7 @@ export default function GenerateClassNames(
   if (typeof options.classNameSlug === 'function') {
     try {
       className = toValidCSSIdentifier(
-        options.classNameSlug(slug, displayName)
+        options.classNameSlug(slug, displayName, slugVars)
       );
     } catch {
       throw new Error(`classNameSlug option must return a string`);
@@ -126,12 +140,6 @@ export default function GenerateClassNames(
   if (typeof options.classNameSlug === 'string') {
     const { classNameSlug } = options;
 
-    // Available variables for the square brackets used in `classNameSlug` options
-    const classNameSlugVars: Record<string, string | null> = {
-      hash: slug,
-      title: displayName,
-    };
-
     // Variables that were used in the config for `classNameSlug`
     const optionVariables = classNameSlug.match(/\[.*?]/g) || [];
     let cnSlug = classNameSlug;
@@ -140,7 +148,10 @@ export default function GenerateClassNames(
       const v = optionVariables[i].slice(1, -1); // Remove the brackets around the variable name
 
       // Replace the var if it key and value exist otherwise place an empty string
-      cnSlug = cnSlug.replace(`[${v}]`, classNameSlugVars[v] || '');
+      cnSlug = cnSlug.replace(
+        `[${v}]`,
+        isSlugVar(v, slugVars) ? slugVars[v] : ''
+      );
     }
 
     className = toValidCSSIdentifier(cnSlug);