refactoring

src/index.ts

@@ -1,5 +1,4 @@
 export * from "./placeholder.js";
-export * from "./pattern.js";
 export * as VariableResolvers from "./resolver/index.js";
 export * from "./resolver/types.js";
 export * as UnknownVariableHandlers from "./unknown-variable-handler/index.js";

src/pattern.ts

@@ -1,17 +0,0 @@
-export class PlaceholderPattern {
-  readonly #prefix: string;
-  readonly #suffix: string;
-
-  public constructor(prefix: string, suffix: string) {
-    this.#prefix = prefix;
-    this.#suffix = suffix;
-  }
-
-  public get prefix() {
-    return this.#prefix;
-  }
-
-  public get suffix() {
-    return this.#suffix;
-  }
-}

src/placeholder.ts

@@ -1,11 +1,14 @@
 import { AbortSubstitutionException, PlaceholderException } from "./exceptions.js";
-import { PlaceholderPattern } from "./pattern.js";
 import { EMPTY as emptyResolver } from "./resolver/index.js";
 import { VariableResolver } from "./resolver/types.js";
-import { StringSection } from "./string-section.js";
 import { UnknownVariableHandler } from "./unknown-variable-handler/types.js";
 import { isDefined, Nullable } from "./utils.js";
 
+export type PlaceholderPattern = {
+  prefix: string;
+  suffix: string;
+};
+
 export type PlaceholderOptions = {
   pattern?: PlaceholderPattern;
   escapeChar?: string;
@@ -14,13 +17,13 @@ export type PlaceholderOptions = {
   unknownVariableHandler?: Nullable<UnknownVariableHandler>;
 };
 
-const DEFAULT_OPTIONS: Required<PlaceholderOptions> = {
-  pattern: new PlaceholderPattern("${", "}"),
+const DEFAULT_OPTIONS: Required<PlaceholderOptions> = Object.freeze({
+  pattern: Object.freeze({ prefix: "${", suffix: "}" }),
   escapeChar: '\\',
   recursive: false,
   resolver: emptyResolver,
   unknownVariableHandler: null
-};
+});
 
 export class PlaceholderSubstitutor {
   readonly #pattern: PlaceholderPattern;
@@ -108,7 +111,7 @@ class Substitutor {
         }
 
         const innerSubstitutor = new Substitutor(this.#substitutor, this.#input.subSection(this.#pos), true);
-        const variable = innerSubstitutor.replace();
+        const variable = innerSubstitutor.replace().trim();
 
         if (variable.length === 0) {
           throw new PlaceholderException(this.#input.getSection(), this.#pos, "Empty variable");
@@ -178,7 +181,7 @@ class Substitutor {
         return this.#substitutor.unknownVariableHandler(this.#substitutor, name);
       } catch (e: any) {
         if (e instanceof AbortSubstitutionException) {
-          throw new PlaceholderException(this.#input.getSection(), this.#pos, "Substitution aborted due to unknown variable", e);
+          throw new PlaceholderException(this.#input.getSection(), this.#pos, `Substitution aborted due to unknown variable: ${name}`, e);
         }
 
         throw new PlaceholderException(this.#input.getSection(), this.#pos, "An error occurred while handling unknown variable", e);
@@ -188,3 +191,59 @@ class Substitutor {
     return null;
   }
 }
+
+class StringSection {
+  readonly #parent: string;
+  readonly #offset: number;
+  readonly #length: number;
+
+  constructor(parent: string, offset: number = 0, length: number = parent.length - offset) {
+    if (offset < 0) {
+      throw new Error("offset < 0");
+    }
+
+    if (length < 0) {
+      throw new Error("length < 0");
+    }
+
+    if (offset + length > parent.length) {
+      throw new Error("offset + length > parent.length");
+    }
+
+    this.#parent = parent;
+    this.#offset = offset;
+    this.#length = length;
+  }
+
+  public get length() {
+    return this.#length;
+  }
+
+  public getSection() {
+    return this.substring(0);
+  }
+
+  public subSection(offset: number = 0, length: number = this.#length - offset) {
+    return new StringSection(this.#parent, this.#offset + offset, length);
+  }
+
+  public charAt(index: number) {
+    return this.#parent.charAt(this.#offset + index);
+  }
+
+  public startsWith(prefix: string, offset: number = 0) {
+    return prefix.length <= (this.#length - offset) && this.#parent.startsWith(prefix, this.#offset + offset);
+  }
+
+  public substring(beginIndex: number = 0, endIndex: number = this.#length - beginIndex) {
+    return this.#parent.substring(this.#offset + beginIndex, this.#offset + endIndex);
+  }
+
+  public toJSON() {
+    return this.getSection();
+  }
+
+  public toString() {
+    return this.getSection();
+  }
+}

src/string-section.ts

@@ -1,55 +0,0 @@
-export class StringSection {
-  readonly #parent: string;
-  readonly #offset: number;
-  readonly #length: number;
-
-  constructor(parent: string, offset: number = 0, length: number = parent.length - offset) {
-    if (offset < 0) {
-      throw new Error("offset < 0");
-    }
-
-    if (length < 0) {
-      throw new Error("length < 0");
-    }
-
-    if (offset + length > parent.length) {
-      throw new Error("offset + length > parent.length");
-    }
-
-    this.#parent = parent;
-    this.#offset = offset;
-    this.#length = length;
-  }
-
-  public get length() {
-    return this.#length;
-  }
-
-  public getSection() {
-    return this.substring(0);
-  }
-
-  public subSection(offset: number = 0, length: number = this.#length - offset) {
-    return new StringSection(this.#parent, this.#offset + offset, length);
-  }
-
-  public charAt(index: number) {
-    return this.#parent.charAt(this.#offset + index);
-  }
-
-  public startsWith(prefix: string, offset: number = 0) {
-    return prefix.length <= (this.#length - offset) && this.#parent.startsWith(prefix, this.#offset + offset);
-  }
-
-  public substring(beginIndex: number = 0, endIndex: number = this.#length - beginIndex) {
-    return this.#parent.substring(this.#offset + beginIndex, this.#offset + endIndex);
-  }
-
-  public toJSON() {
-    return this.getSection();
-  }
-
-  public toString() {
-    return this.getSection();
-  }
-}