Handle new Bublé template string compilation. (#155)

bublejs/buble#67 changed Bublé template strings to compile similarly to Babel ones, for spec reasons.
With this patch, the new style as well as the old style are detected correctly.

package.json

@@ -23,6 +23,7 @@
   "dependencies": {
     "@choojs/findup": "^0.2.0",
     "acorn-node": "^1.3.0",
+    "estree-is-member-expression": "^1.0.0",
     "fast-json-parse": "^1.0.2",
     "insert-css": "^2.0.0",
     "map-limit": "0.0.1",

transform.js

@@ -1,3 +1,4 @@
+const isMemberExpression = require('estree-is-member-expression')
 const cssResolve = require('style-resolve').sync
 const transformAst = require('transform-ast')
 const staticEval = require('static-eval')
@@ -18,6 +19,13 @@ function isBabelTemplateDefinition (node) {
     node.callee.type === 'Identifier' && node.callee.name === '_taggedTemplateLiteral'
 }
 
+function isBubleTemplateDefinition (node) {
+  return node.type === 'CallExpression' &&
+    isMemberExpression(node.callee, 'Object.freeze') &&
+    node.arguments[0] && node.arguments[0].type === 'ArrayExpression' &&
+    node.arguments[0].elements.every(function (el) { return el.type === 'Literal' })
+}
+
 // inline sheetify transform for browserify
 // obj -> (str, opts) -> str
 function transform (filename, options) {
@@ -61,6 +69,7 @@ function transform (filename, options) {
     // judge us too harshly, we'll work on perf ✨soon✨ -yw
     const nodes = []
     const babelTemplateObjects = {}
+    const bubleTemplateObjects = {}
     const src = Buffer.concat(bufs).toString('utf8')
     var mname = null
     var ast
@@ -117,11 +126,17 @@ function transform (filename, options) {
       var css
       var elements
 
-      if (node.type === 'VariableDeclarator' && node.init && isBabelTemplateDefinition(node.init)) {
-        // Babel generates helper calls like
-        //    _taggedTemplateLiteral([":host .class { color: hotpink; }"], [":host .class { color: hotpink; }"])
-        // we only keep the "cooked" part
-        babelTemplateObjects[node.id.name] = node.init.arguments[0]
+      if (node.type === 'VariableDeclarator' && node.init) {
+        if (isBabelTemplateDefinition(node.init)) {
+          // Babel generates helper calls like
+          //    _taggedTemplateLiteral([":host .class { color: hotpink; }"], [":host .class { color: hotpink; }"])
+          // we only keep the "cooked" part
+          babelTemplateObjects[node.id.name] = node.init.arguments[0]
+        } else if (isBubleTemplateDefinition(node.init)) {
+          // Buble generates helper calls like
+          //    Object.freeze([":host .class { color: hotpink; }"])
+          bubleTemplateObjects[node.id.name] = node.init.arguments[0]
+        }
       }
 
       if (node.type === 'TemplateLiteral' && node.parent && node.parent.tag) {
@@ -146,7 +161,12 @@ function transform (filename, options) {
         } else if (node.arguments[0] && node.arguments[0].type === 'Identifier') {
           // Babel generates code like
           //    sheetify(_templateObject)
-          elements = babelTemplateObjects[node.arguments[0].name].elements
+          var arg = node.arguments[0].name
+          if (babelTemplateObjects[arg]) {
+            elements = babelTemplateObjects[arg].elements
+          } else if (bubleTemplateObjects[arg]) {
+            elements = bubleTemplateObjects[arg].elements
+          }
         }
 
         if (elements) {