Change implementation strategy of cashassembly, add scripts, comments support and tests

source/cash-assembly/identifier-collisions.ts

@@ -0,0 +1,59 @@
+import { generateBytecodeMap, IdentifierResolutionType, OpcodesBchSpec } from '@bitauth/libauth';
+import { CashAssemblyIdentifierCollisionError } from './errors.ts';
+import type { CompileCashAssemblyContext } from './types.ts';
+
+/**
+ * Set of opcode names that the compiler recognizes.
+ */
+const COMPILER_OPCODE_NAMES: ReadonlySet<string> = new Set(Object.keys(generateBytecodeMap(OpcodesBchSpec)));
+
+/**
+ * Parameters for {@link assertNoIdentifierCollisions} function.
+ */
+export type AssertNoIdentifierCollisionsParameters = Pick<CompileCashAssemblyContext, 'variables' | 'templateScripts'>;
+
+/**
+ * Libauth resolves opcodes, then variables, then scripts, and the first match silently hides the
+ * rest, leading to unexpected compilation results and no errors. This function throws when one identifier matches more than one resolution type.
+ *
+ * @param {AssertNoIdentifierCollisionsParameters} parameters - Provided variables and optional template scripts.
+ * @throws {@link CashAssemblyIdentifierCollisionError} - When one identifier matches more than one resolution type.
+ */
+export const assertNoIdentifierCollisions = (parameters: AssertNoIdentifierCollisionsParameters): void => {
+    const { variables, templateScripts } = parameters;
+
+    // Create a set of the script identifiers from the template scripts map.
+    const scriptIdentifiers = new Set(Object.keys(templateScripts ?? {}));
+
+    const variableNames = new Set(Object.keys(variables));
+
+    // Combine both, the variableNames and the scriptIdentifiers, to get a set of all identifiers.
+    const declaredIdentifiers = new Set([ ...variableNames, ...scriptIdentifiers ]);
+
+    // This loop will check for more than one occurrence of an identifier in OP_CODES, variables, and scripts
+    for (const identifier of declaredIdentifiers) {
+        // Resolution types is a native construct from libauth.
+        const resolutionTypes: IdentifierResolutionType[] = [];
+
+        // If the identifier is an opcode, then push it to the resolution types array, this will also be
+        // detected by either or both of the variableNames and scriptIdentifiers checks.
+        if (COMPILER_OPCODE_NAMES.has(identifier) === true) {
+            resolutionTypes.push(IdentifierResolutionType.opcode);
+        }
+
+        // If the identifier is in variables, then push it to the resolution types array.
+        if (variableNames.has(identifier) === true) {
+            resolutionTypes.push(IdentifierResolutionType.variable);
+        }
+
+        // If the identifier is a script identifier, then push it to the resolution types array.
+        if (scriptIdentifiers.has(identifier) === true) {
+            resolutionTypes.push(IdentifierResolutionType.script);
+        }
+
+        // If there are more than one resolution types, then throw an error.
+        if (resolutionTypes.length > 1) {
+            throw new CashAssemblyIdentifierCollisionError(identifier, resolutionTypes);
+        }
+    }
+};