feat: Adding a new class of errors - MultipleCssBlockErrors.

Author: ramitha

packages/@css-blocks/core/src/BlockTree/Block.ts

@@ -14,7 +14,7 @@ import { isAttributeNode, isClassNode } from "../BlockParser";
 import { isRootNode, toAttrToken } from "../BlockParser";
 import { BlockPath, CLASS_NAME_IDENT, DEFAULT_EXPORT, ROOT_CLASS } from "../BlockSyntax";
 import { ResolvedConfiguration } from "../configuration";
-import { CssBlockError, InvalidBlockSyntax } from "../errors";
+import { CssBlockError, InvalidBlockSyntax, MultipleCssBlockErrors } from "../errors";
 import { FileIdentifier } from "../importing";
 import { SourceFile, SourceRange } from "../SourceLocation";
 
@@ -51,6 +51,7 @@ export class Block
   private _blockExportReverseLookup: Map<Block, string> = new Map();
   private _identifier: FileIdentifier;
   private _implements: Block[] = [];
+  private _blockErrors: CssBlockError[] = [];
   private hasHadNameReset = false;
 
   public readonly guid: string;
@@ -185,6 +186,25 @@ export class Block
     return attr || klass || undefined;
   }
 
+  /**
+   * Stores a block error along with the block
+   * @param error CssBlockError that is added to the block
+   */
+  addError(error: CssBlockError) {
+    this._blockErrors.push(error);
+  }
+
+  /**
+   * Checks for errors on the block
+   * @returns true if the block is valid else throws the errors on the block
+   */
+  assertValid(): Boolean {
+    if (this._blockErrors.length) {
+      throw new MultipleCssBlockErrors(this._blockErrors);
+    }
+    return true;
+  }
+
   /**
    * Add an absolute, normalized path as a compilation dependency. This is used
    * to invalidate caches and trigger watchers when those files change.

packages/@css-blocks/core/src/errors.ts

@@ -127,3 +127,21 @@ export class BlockPathError extends CssBlockError {
     if (details) { this.message += `\n${details}`; }
   }
 }
+
+/**
+ * Acts as a collection of CssBlockErrors along with utility methods to add and
+ * clear errors
+ */
+export class MultipleCssBlockErrors extends Error {
+  private _errors: CssBlockError[] = [];
+  constructor(errors: CssBlockError[]) {
+    super();
+    this._errors = errors;
+  }
+  add(error:CssBlockError) {
+    this._errors.push(error);
+  }
+  clear() {
+    this._errors = [];
+  }
+}