add initial hover provider

packages/tailwindcss-language-server/package.json

@@ -19,6 +19,7 @@
     "@babel/register": "^7.9.0",
     "@types/node": "^13.9.3",
     "@zeit/ncc": "^0.22.0",
+    "css.escape": "^1.5.1",
     "dlv": "^1.1.3",
     "glob-exec": "^0.1.1",
     "tailwindcss-class-names": "0.0.1",

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

@@ -13,7 +13,7 @@ import { getColor, getColorFromString } from '../util/color'
 import { isHtmlContext } from '../util/html'
 import { isCssContext } from '../util/css'
 import { findLast, findJsxStrings, arrFindLast } from '../util/find'
-import { stringifyConfigValue } from '../util/stringify'
+import { stringifyConfigValue, stringifyCss } from '../util/stringify'
 import isObject from '../util/isObject'
 
 function completionsFromClassList(
@@ -343,25 +343,6 @@ function stringifyDecls(obj: any): string {
     .join(' ')
 }
 
-function stringifyCss(obj: any, indent: number = 0): string {
-  let indentStr = '  '.repeat(indent)
-  if (obj.__decls === true) {
-    return Object.keys(removeMeta(obj))
-      .reduce((acc, curr, i) => {
-        return `${acc}${i === 0 ? '' : '\n'}${indentStr}${curr}: ${obj[curr]};`
-      }, '')
-      .trim()
-  }
-  return Object.keys(removeMeta(obj))
-    .reduce((acc, curr, i) => {
-      return `${acc}${i === 0 ? '' : '\n'}${indentStr}${curr} {\n${stringifyCss(
-        obj[curr],
-        indent + 2
-      )}\n${indentStr}}`
-    }, '')
-    .trim()
-}
-
 function getCssDetail(state: State, className: any): string {
   if (Array.isArray(className)) {
     return `${className.length} rules`

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

@@ -0,0 +1,56 @@
+import { State } from '../util/state'
+import { Hover, TextDocumentPositionParams } from 'vscode-languageserver'
+import {
+  getClassNameAtPosition,
+  getClassNameParts,
+} from '../util/getClassNameAtPosition'
+import { stringifyCss } from '../util/stringify'
+const dlv = require('dlv')
+import escapeClassName from 'css.escape'
+import { isHtmlContext } from '../util/html'
+
+export function provideHover(
+  state: State,
+  params: TextDocumentPositionParams
+): Hover {
+  let doc = state.editor.documents.get(params.textDocument.uri)
+
+  if (isHtmlContext(doc, params.position)) {
+    return provideClassNameHover(state, params)
+  }
+
+  return null
+}
+
+function provideClassNameHover(
+  state: State,
+  { textDocument, position }: TextDocumentPositionParams
+): Hover {
+  let doc = state.editor.documents.get(textDocument.uri)
+  let hovered = getClassNameAtPosition(doc, position)
+  if (!hovered) return null
+
+  const parts = getClassNameParts(state, hovered.className)
+  if (parts === null) return null
+
+  return {
+    contents: {
+      language: 'css',
+      value: stringifyCss(dlv(state.classNames.classNames, parts), {
+        selector: augmentClassName(parts, state),
+      }),
+    },
+    range: hovered.range,
+  }
+}
+
+// TODO
+function augmentClassName(className: string | string[], state: State): string {
+  const parts = Array.isArray(className)
+    ? className
+    : getClassNameParts(state, className)
+  const obj = dlv(state.classNames.classNames, parts)
+  const pseudo = obj.__pseudo ? obj.__pseudo.join('') : ''
+  const scope = obj.__scope ? `${obj.__scope} ` : ''
+  return `${scope}.${escapeClassName(parts.join(state.separator))}${pseudo}`
+}

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

@@ -13,6 +13,8 @@ import {
   InitializeResult,
   CompletionParams,
   CompletionList,
+  Hover,
+  TextDocumentPositionParams,
 } from 'vscode-languageserver'
 import getTailwindState from 'tailwindcss-class-names'
 import { State } from './util/state'
@@ -20,6 +22,7 @@ import {
   provideCompletions,
   resolveCompletionItem,
 } from './providers/completionProvider'
+import { provideHover } from './providers/hoverProvider'
 import { URI } from 'vscode-uri'
 
 let state: State = null
@@ -62,6 +65,7 @@ connection.onInitialize(
           resolveProvider: true,
           triggerCharacters: ['"', "'", '`', ' ', '.', '[', state.separator],
         },
+        hoverProvider: true,
       },
     }
   }
@@ -88,4 +92,10 @@ connection.onCompletionResolve(
   }
 )
 
+connection.onHover(
+  (params: TextDocumentPositionParams): Hover => {
+    return provideHover(state, params)
+  }
+)
+
 connection.listen()

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

@@ -0,0 +1,95 @@
+import { TextDocument, Range, Position } from 'vscode-languageserver'
+import { State } from './state'
+const dlv = require('dlv')
+
+export function getClassNameAtPosition(
+  document: TextDocument,
+  position: Position
+): { className: string; range: Range } {
+  const range1: Range = {
+    start: { line: Math.max(position.line - 5, 0), character: 0 },
+    end: position,
+  }
+  const text1: string = document.getText(range1)
+
+  if (!/\bclass(Name)?=['"][^'"]*$/.test(text1)) return null
+
+  const range2: Range = {
+    start: { line: Math.max(position.line - 5, 0), character: 0 },
+    end: { line: position.line + 1, character: position.character },
+  }
+  const text2: string = document.getText(range2)
+
+  let str: string = text1 + text2.substr(text1.length).match(/^([^"' ]*)/)[0]
+  let matches: RegExpMatchArray = str.match(/\bclass(Name)?=["']([^"']+)$/)
+
+  if (!matches) return null
+
+  let className: string = matches[2].split(' ').pop()
+  if (!className) return null
+
+  let range: Range = {
+    start: {
+      line: position.line,
+      character:
+        position.character + str.length - text1.length - className.length,
+    },
+    end: {
+      line: position.line,
+      character: position.character + str.length - text1.length,
+    },
+  }
+
+  return { className, range }
+}
+
+export function getClassNameParts(state: State, className: string): string[] {
+  let separator = state.separator
+  className = className.replace(/^\./, '')
+  let parts: string[] = className.split(separator)
+
+  if (parts.length === 1) {
+    return dlv(state.classNames.classNames, [className, '__rule']) === true
+      ? [className]
+      : null
+  }
+
+  let points = combinations('123456789'.substr(0, parts.length - 1)).map((x) =>
+    x.split('').map((x) => parseInt(x, 10))
+  )
+
+  let possibilities: string[][] = [
+    [className],
+    ...points.map((p) => {
+      let result = []
+      let i = 0
+      p.forEach((x) => {
+        result.push(parts.slice(i, x).join('-'))
+        i = x
+      })
+      result.push(parts.slice(i).join('-'))
+      return result
+    }),
+  ]
+
+  return possibilities.find((key) => {
+    if (dlv(state.classNames.classNames, [...key, '__rule']) === true) {
+      return true
+    }
+    return false
+  })
+}
+
+function combinations(str: string): string[] {
+  let fn = function (active: string, rest: string, a: string[]) {
+    if (!active && !rest) return
+    if (!rest) {
+      a.push(active)
+    } else {
+      fn(active + rest[0], rest.slice(1), a)
+      fn(active, rest.slice(1), a)
+    }
+    return a
+  }
+  return fn('', str, [])
+}

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

@@ -1,11 +1,45 @@
+import removeMeta from './removeMeta'
+
 export function stringifyConfigValue(x: any): string {
   if (typeof x === 'string') return x
   if (typeof x === 'number') return x.toString()
   if (Array.isArray(x)) {
     return x
-      .filter(y => typeof y === 'string')
+      .filter((y) => typeof y === 'string')
       .filter(Boolean)
       .join(', ')
   }
   return ''
 }
+
+export function stringifyCss(
+  obj: any,
+  { indent = 0, selector }: { indent?: number; selector?: string } = {}
+): string {
+  let indentStr = '\t'.repeat(indent)
+  if (obj.__decls === true) {
+    let before = ''
+    let after = ''
+    if (selector) {
+      before = `${indentStr}${selector} {\n`
+      after = `\n${indentStr}}`
+      indentStr += '\t'
+    }
+    return (
+      before +
+      Object.keys(removeMeta(obj)).reduce((acc, curr, i) => {
+        return `${acc}${i === 0 ? '' : '\n'}${indentStr}${curr}: ${obj[curr]};`
+      }, '') +
+      after
+    )
+  }
+  return Object.keys(removeMeta(obj)).reduce((acc, curr, i) => {
+    return `${acc}${i === 0 ? '' : '\n'}${indentStr}${curr} {\n${stringifyCss(
+      obj[curr],
+      {
+        indent: indent + 1,
+        selector,
+      }
+    )}\n${indentStr}}`
+  }, '')
+}