feat(preprocess): add optimizeCarbonImports preprocessor (#499)

preprocess/optimize-carbon-imports.js

@@ -0,0 +1,97 @@
+const fs = require("fs");
+const path = require("path");
+const { parse, walk } = require("svelte/compiler");
+const api = require("./api.json");
+
+const carbon = {
+  components: "carbon-components-svelte",
+  icons: "carbon-icons-svelte",
+  pictograms: "carbon-pictograms-svelte",
+};
+
+function getPackageJson() {
+  const path_pkg = path.join(process.cwd(), "package.json");
+
+  if (fs.existsSync(path_pkg)) {
+    return JSON.parse(fs.readFileSync(path_pkg, "utf-8"));
+  } else {
+    return {};
+  }
+}
+
+function getCarbonVersions() {
+  const pkg = getPackageJson();
+  const devDeps = pkg.devDependencies || {};
+  const deps = pkg.dependencies || {};
+
+  return [carbon.components, carbon.icons, carbon.pictograms].reduce((a, c) => {
+    let version = devDeps[c] || deps[c];
+
+    if (version !== undefined) {
+      const [major, minor, patch] = version.replace(/^(\^|\~)/, "").split(".");
+      version = major;
+    }
+
+    return { ...a, [c]: version };
+  }, {});
+}
+
+const versions = getCarbonVersions();
+
+function optimizeCarbonImports() {
+  return {
+    script: ({ content, filename }) => {
+      if (/node_modules/.test(filename)) return { code: content };
+
+      const ast = parse(`<script>${content}</script>`, { filename });
+
+      let cursor = -8;
+
+      function replaceContent(node, onSpecifier) {
+        const replacer = node.specifiers.map((i) => onSpecifier(i)).join("\n");
+        const replacee = content.slice(node.start + cursor, node.end + cursor);
+
+        content = content.replace(replacee, replacer);
+        cursor += replacer.length - replacee.length;
+      }
+
+      walk(ast.instance, {
+        enter(node) {
+          if (node.type === "ImportDeclaration") {
+            switch (node.source.value) {
+              case carbon.components:
+                replaceContent(node, ({ local, imported }) => {
+                  return `import ${local.name} from "${
+                    api.components[imported.name].path
+                  }";`;
+                });
+                break;
+
+              case carbon.icons:
+                replaceContent(node, ({ local, imported }) => {
+                  return `import ${local.name} from "carbon-icons-svelte/lib/${imported.name}/${imported.name}.svelte";`;
+                });
+                break;
+
+              case carbon.pictograms:
+                replaceContent(node, ({ local, imported }) => {
+                  if (versions[carbon.pictograms] === "11") {
+                    return `import ${local.name} from "carbon-pictograms-svelte/lib/${imported.name}.svelte";`;
+                  }
+
+                  return `import ${local.name} from "carbon-pictograms-svelte/lib/${imported.name}/${imported.name}.svelte";`;
+                });
+                break;
+            }
+          }
+        },
+      });
+
+      return { code: content };
+    },
+  };
+}
+
+module.exports = {
+  optimizeCarbonImports,
+};