add @apply hover provider

packages/tailwindcss-language-server/package.json

@@ -23,6 +23,7 @@
     "dlv": "^1.1.3",
     "emmet-helper": "0.0.1",
     "glob-exec": "^0.1.1",
+    "line-column": "^1.0.2",
     "tailwindcss-class-names": "0.0.1",
     "typescript": "^3.8.3",
     "vscode-languageserver": "^5.2.1",

packages/tailwindcss-language-server/src/providers/hoverProvider.ts

@@ -1,4 +1,4 @@
-import { State } from '../util/state'
+import { State, DocumentClassName } from '../util/state'
 import { Hover, TextDocumentPositionParams } from 'vscode-languageserver'
 import {
   getClassNameAtPosition,
@@ -9,6 +9,8 @@ const dlv = require('dlv')
 import { isHtmlContext } from '../util/html'
 import { isCssContext } from '../util/css'
 import { isJsContext } from '../util/js'
+import { isWithinRange } from '../util/isWithinRange'
+import { findClassNamesInRange } from '../util/find'
 
 export function provideHover(
   state: State,
@@ -73,7 +75,7 @@ function provideCssHelperHover(
   }
 }
 
-function provideClassNameHover(
+function provideClassAttributeHover(
   state: State,
   { textDocument, position }: TextDocumentPositionParams
 ): Hover {
@@ -84,17 +86,53 @@ function provideClassNameHover(
   let hovered = getClassNameAtPosition(doc, position)
   if (!hovered) return null
 
-  const parts = getClassNameParts(state, hovered.className)
+  return classNameToHover(state, hovered)
+}
+
+function classNameToHover(
+  state: State,
+  { className, range }: DocumentClassName
+): Hover {
+  const parts = getClassNameParts(state, className)
   if (parts === null) return null
 
   return {
     contents: {
       language: 'css',
-      value: stringifyCss(
-        hovered.className,
-        dlv(state.classNames.classNames, parts)
-      ),
+      value: stringifyCss(className, dlv(state.classNames.classNames, parts)),
     },
-    range: hovered.range,
+    range,
   }
 }
+
+function provideAtApplyHover(
+  state: State,
+  { textDocument, position }: TextDocumentPositionParams
+): Hover {
+  let doc = state.editor.documents.get(textDocument.uri)
+
+  if (!isCssContext(doc, position)) return null
+
+  const classNames = findClassNamesInRange(doc, {
+    start: { line: Math.max(position.line - 10, 0), character: 0 },
+    end: { line: position.line + 10, character: 0 },
+  })
+
+  const className = classNames.find(({ range }) =>
+    isWithinRange(position, range)
+  )
+
+  if (!className) return null
+
+  return classNameToHover(state, className)
+}
+
+function provideClassNameHover(
+  state: State,
+  params: TextDocumentPositionParams
+): Hover {
+  return (
+    provideClassAttributeHover(state, params) ||
+    provideAtApplyHover(state, params)
+  )
+}

packages/tailwindcss-language-server/src/util/find.ts

@@ -1,3 +1,7 @@
+import { TextDocument, Range, Position } from 'vscode-languageserver'
+import { DocumentClassName, DocumentClassList } from './state'
+import lineColumn from 'line-column'
+
 export function findAll(re: RegExp, str: string): RegExpMatchArray[] {
   let match: RegExpMatchArray
   let matches: RegExpMatchArray[] = []
@@ -65,3 +69,76 @@ export function findJsxStrings(str: string): StringInfo[] {
   }
   return strings
 }
+
+export function findClassNamesInRange(
+  doc: TextDocument,
+  range: Range
+): DocumentClassName[] {
+  const classLists = findClassListsInRange(doc, range)
+  return [].concat.apply(
+    [],
+    classLists.map(({ classList, range }) => {
+      const parts = classList.split(/(\s+)/)
+      const names: DocumentClassName[] = []
+      let index = 0
+      for (let i = 0; i < parts.length; i++) {
+        if (i % 2 === 0) {
+          const start = indexToPosition(classList, index)
+          const end = indexToPosition(classList, index + parts[i].length)
+          names.push({
+            className: parts[i],
+            range: {
+              start: {
+                line: range.start.line + start.line,
+                character:
+                  (end.line === 0 ? range.start.character : 0) +
+                  start.character,
+              },
+              end: {
+                line: range.start.line + end.line,
+                character:
+                  (end.line === 0 ? range.start.character : 0) + end.character,
+              },
+            },
+          })
+        }
+        index += parts[i].length
+      }
+      return names
+    })
+  )
+}
+
+export function findClassListsInRange(
+  doc: TextDocument,
+  range: Range
+): DocumentClassList[] {
+  const text = doc.getText(range)
+  const matches = findAll(/(@apply\s+)(?<classList>[^;}]+)[;}]/g, text)
+
+  return matches.map((match) => {
+    const start = indexToPosition(text, match.index + match[1].length)
+    const end = indexToPosition(
+      text,
+      match.index + match[1].length + match.groups.classList.length
+    )
+    return {
+      classList: match.groups.classList,
+      range: {
+        start: {
+          line: range.start.line + start.line,
+          character: range.start.character + start.character,
+        },
+        end: {
+          line: range.start.line + end.line,
+          character: range.start.character + end.character,
+        },
+      },
+    }
+  })
+}
+
+function indexToPosition(str: string, index: number): Position {
+  const { line, col } = lineColumn(str + '\n', index)
+  return { line: line - 1, character: col - 1 }
+}

packages/tailwindcss-language-server/src/util/getClassNameAtPosition.ts

@@ -1,11 +1,11 @@
 import { TextDocument, Range, Position } from 'vscode-languageserver'
-import { State } from './state'
+import { State, DocumentClassName } from './state'
 const dlv = require('dlv')
 
 export function getClassNameAtPosition(
   document: TextDocument,
   position: Position
-): { className: string; range: Range } {
+): DocumentClassName {
   const range1: Range = {
     start: { line: Math.max(position.line - 5, 0), character: 0 },
     end: position,

packages/tailwindcss-language-server/src/util/isWithinRange.ts

@@ -0,0 +1,34 @@
+import { Position, Range } from 'vscode-languageserver'
+
+export function isWithinRange(position: Position, range: Range): boolean {
+  if (
+    position.line === range.start.line &&
+    position.character >= range.start.character
+  ) {
+    if (
+      position.line === range.end.line &&
+      position.character > range.end.character
+    ) {
+      return false
+    } else {
+      return true
+    }
+  }
+  if (
+    position.line === range.end.line &&
+    position.character <= range.end.character
+  ) {
+    if (
+      position.line === range.start.line &&
+      position.character < range.end.character
+    ) {
+      return false
+    } else {
+      return true
+    }
+  }
+  if (position.line > range.start.line && position.line < range.end.line) {
+    return true
+  }
+  return false
+}

packages/tailwindcss-language-server/src/util/state.ts

@@ -1,4 +1,4 @@
-import { TextDocuments, Connection } from 'vscode-languageserver'
+import { TextDocuments, Connection, Range } from 'vscode-languageserver'
 
 export type ClassNamesTree = {
   [key: string]: ClassNamesTree
@@ -36,3 +36,13 @@ export type State = null | {
   dependencies: string[]
   editor: EditorState
 }
+
+export type DocumentClassList = {
+  classList: string
+  range: Range
+}
+
+export type DocumentClassName = {
+  className: string
+  range: Range
+}