Add flag to disable "touch" files in favour of registering directory dependencies (#162)

* use context dependencies and remove file watcher and touch files

* remove broken bail out

* register glob base dirs as dependency as well as context-dependency

improves tooling compatibility: now works with postcss-cli and rollup, as well as webpack

* add parse-glob dependency

* fix fresh context build

* rejig config dependency tracking

* replace ??

* put context dependencies behind TAILWIND_DISABLE_TOUCH flag

* move file modified map to context

* don't start watcher if touch is disabled

Author: bradlc

package-lock.json

@@ -20,6 +20,7 @@
     "lodash.topath": "^4.5.2",
     "normalize-path": "^3.0.0",
     "object-hash": "^2.1.1",
+    "parse-glob": "^3.0.4",
     "postcss-selector-parser": "^6.0.4",
     "quick-lru": "^5.1.1"
   },

package.json

@@ -23,9 +23,9 @@ module.exports = (configOrPath = {}) => {
           return root
         },
       function (root, result) {
-        function registerDependency(fileName) {
+        function registerDependency(fileName, type = 'dependency') {
           result.messages.push({
-            type: 'dependency',
+            type,
             plugin: 'tailwindcss-jit',
             parent: result.opts.from,
             file: fileName,
@@ -36,8 +36,10 @@ module.exports = (configOrPath = {}) => {
 
         let context = setupContext(configOrPath)(result, root)
 
-        if (context.configPath !== null) {
-          registerDependency(context.configPath)
+        if (!env.TAILWIND_DISABLE_TOUCH) {
+          if (context.configPath !== null) {
+            registerDependency(context.configPath)
+          }
         }
 
         return postcss([

src/index.js

@@ -1,6 +1,7 @@
 const fs = require('fs')
 const path = require('path')
 const fastGlob = require('fast-glob')
+const parseGlob = require('parse-glob')
 const sharedState = require('./sharedState')
 const { generateRules } = require('./generateRules')
 const { bigSign, cloneNodes } = require('./utils')
@@ -141,21 +142,55 @@ function expandTailwindAtRules(context, registerDependency) {
 
     // ---
 
-    // Register our temp file as a dependency — we write to this file
-    // to trigger rebuilds.
-    if (context.touchFile) {
-      registerDependency(context.touchFile)
-    }
+    if (sharedState.env.TAILWIND_DISABLE_TOUCH) {
+      for (let maybeGlob of context.candidateFiles) {
+        let {
+          is: { glob: isGlob },
+          base,
+        } = parseGlob(maybeGlob)
+
+        if (isGlob) {
+          // register base dir as `dependency` _and_ `context-dependency` for
+          // increased compatibility
+          registerDependency(path.resolve(base))
+          registerDependency(path.resolve(base), 'context-dependency')
+        } else {
+          registerDependency(path.resolve(maybeGlob))
+        }
+      }
 
-    // If we're not set up and watching files ourselves, we need to do
-    // the work of grabbing all of the template files for candidate
-    // detection.
-    if (!context.scannedContent) {
+      env.DEBUG && console.time('Finding changed files')
       let files = fastGlob.sync(context.candidateFiles)
       for (let file of files) {
-        context.changedFiles.add(file)
+        let prevModified = context.fileModifiedMap.has(file)
+          ? context.fileModifiedMap.get(file)
+          : -Infinity
+        let modified = fs.statSync(file).mtimeMs
+
+        if (!context.scannedContent || modified > prevModified) {
+          context.changedFiles.add(file)
+          context.fileModifiedMap.set(file, modified)
+        }
       }
       context.scannedContent = true
+      env.DEBUG && console.timeEnd('Finding changed files')
+    } else {
+      // Register our temp file as a dependency — we write to this file
+      // to trigger rebuilds.
+      if (context.touchFile) {
+        registerDependency(context.touchFile)
+      }
+
+      // If we're not set up and watching files ourselves, we need to do
+      // the work of grabbing all of the template files for candidate
+      // detection.
+      if (!context.scannedContent) {
+        let files = fastGlob.sync(context.candidateFiles)
+        for (let file of files) {
+          context.changedFiles.add(file)
+        }
+        context.scannedContent = true
+      }
     }
 
     // ---