jonschlinkert · June 20, 2022 07:22 · Jun 20, 2022
diff --git a/prisma-framents-poc.js b/prisma-framents-poc.js
@@ -0,0 +1,122 @@
+const NEWLINE_REGEX = /\r?\n/;
+const INCLUDE_REGEX = /^(\s*)include\(([A-Z][0-9a-zA-Z]*?)\)/;
+const SECTION_START_REGEX = /^([a-z]+) ([A-Z][0-9a-zA-Z]*?)\s*{/;
+const SECTION_END_REGEX   = /(?<=})/;
+
+class Section {
+  type = '';
+  name = '';
+  leading = [];
+  body = [];
+
+  expand(fragments = {}) {
+    const body = [this.leading];
+
+    for (let i = 0; i < this.body.length; i++) {
+      const line = this.body[i];
+      const match = INCLUDE_REGEX.exec(line);
+
+      if (!match) {
+        body.push(line);
+        continue;
+      }
+
+      if (!fragments[match[2]]) {
+        throw new SyntaxError('Invalid fragment name: ' + match[2]);
+      }
+
+      body.push(...fragments[match[2]].map(f => match[1] + f.trim()));
+    }
+
+    return body.join('\n');
+  }
+
+  stringify() {
+    return [this.leading, ...this.body].join('\n');
+  }
+}
+
+class PreProcessor {
+  constructor(source = '', fragments) {
+    this.source = source;
+    this.sections = [];
+    this.fragments = { ...fragments };
+  }
+
+  tokenize() {
+    for (const chunk of this.source.split(SECTION_END_REGEX)) {
+      const lines = chunk.split(NEWLINE_REGEX);
+      const section = new Section();
+      let prev;
+
+      while (lines.length) {
+        const match = SECTION_START_REGEX.exec(lines[0]);
+
+        if (match) {
+          section.type = match[1];
+          section.name = match[2];
+          section.body = lines;
+          this.sections.push(section);
+
+          if (section.type === 'fragment' && !this.fragments[section.name]) {
+            this.fragments[section.name] = section.body.slice(1, -1);
+          }
+          break;
+        } else if (!(prev === '' && lines[0] === '')) {
+          section.leading.push(lines[0]);
+        }
+
+        prev = lines[0];
+        section.body.push(lines.shift());
+      }
+
+      section.leading = section.leading.join('\n');
+    }
+
+    return this.sections;
+  }
+
+  stringify() {
+    return this.sections.map(s => s.stringify()).join('\n');
+  }
+
+  expand(fragments = this.fragments) {
+    if (!this.sections.length) this.tokenize();
+    return this.sections.map(s => s.expand(fragments)).join('\n');
+  }
+}
+
+module.exports = PreProcessor;
+
+const string = `
+fragment Basics {
+  updatedAt DateTime @updatedAt
+  createdAt DateTime @default(now())
+}
+
+//
+// This
+// is a
+// comment
+//
+
+model User {
+  include(Id)
+  include(Basics)
+}
+
+model Task {
+  include(Id)
+  include(Basics)
+}
+`;
+
+const preprocessor = new PreProcessor(string, {
+  Id: ['id String @id @default(cuid())']
+});
+
+// const sections = preprocessor.tokenize();
+// console.log(preprocessor);
+// console.log(preprocessor.stringify());
+const expanded = preprocessor.expand();
+console.log(expanded);