refactor(if_match): move if-match parser module

Author: TomokiMiyauci

if_match.ts

@@ -0,0 +1,24 @@
+// Copyright 2023-latest the httpland authors. All rights reserved. MIT license.
+// This module is browser compatible.
+
+// TODO(miyauci): External Packaging
+
+import { type ETag, parseETag } from "./deps.ts";
+
+export type IfMatch = Star | ETag[];
+export type IfNoneMatch = IfMatch;
+export type Star = "*";
+
+/** Parses string into {@link IfMatch}({@link IfNoneMatch}).
+ * @throws {SyntaxError} If the input is invalid.
+ */
+export function parse(input: string): IfMatch | IfNoneMatch {
+  input = input.trim();
+
+  if (input === "*") return input;
+
+  return input
+    .split(",")
+    .filter(Boolean)
+    .map(parseETag);
+}

if_match_test.ts

@@ -0,0 +1,71 @@
+import { parse } from "./if_match.ts";
+import { type ETag } from "./deps.ts";
+import { assertEquals, assertThrows, describe, it } from "./_dev_deps.ts";
+
+describe("parse", () => {
+  it("should return star", () => {
+    const table: string[] = [
+      "*",
+      " *",
+      "* ",
+      "   *  ",
+    ];
+
+    table.forEach((input) => {
+      assertEquals(parse(input), "*");
+    });
+  });
+
+  it("should return empty list", () => {
+    const table: string[] = [
+      "",
+      "     ",
+    ];
+
+    table.forEach((input) => {
+      assertEquals(parse(input), []);
+    });
+  });
+
+  it("should return etag list", () => {
+    const table: [string, ETag[]][] = [
+      [`""`, [{ tag: "", weak: false }]],
+      [`"", "a", "b"`, [{ tag: "", weak: false }, { tag: "a", weak: false }, {
+        tag: "b",
+        weak: false,
+      }]],
+      [`W/"", "a", W/"abc"`, [{ tag: "", weak: true }, {
+        tag: "a",
+        weak: false,
+      }, {
+        tag: "abc",
+        weak: true,
+      }]],
+      [`"", "*"`, [{ tag: "", weak: false }, {
+        tag: "*",
+        weak: false,
+      }]],
+    ];
+
+    table.forEach(([input, expected]) => {
+      assertEquals(parse(input), expected);
+    });
+  });
+
+  it("should throw error if the input is invalid syntax", () => {
+    const table: string[] = [
+      `"`,
+      "* a",
+      "*,",
+      `*, ""`,
+      `","`,
+      `* *`,
+      `**`,
+      `"", *`,
+    ];
+
+    table.forEach((input) => {
+      assertThrows(() => parse(input));
+    });
+  });
+});

preconditions/utils.ts

@@ -9,6 +9,7 @@ import {
   parseHttpDate,
   RepresentationHeader,
 } from "../deps.ts";
+import { parse } from "../if_match.ts";
 
 /** Match `If-Match` field and `ETag` field.
  * @throws {SyntaxError} If the input is invalid syntax.
@@ -158,18 +159,3 @@ export function isBannedHeader(fieldName: string): boolean {
 }
 
 export type Star = "*";
-export type IfNoneMatch = Star | ETag[];
-export type IfMatch = IfNoneMatch;
-
-/**
- * @throws {SyntaxError} If the input is invalid.
- */
-export function parse(input: string): IfMatch | IfNoneMatch {
-  input = input.trim();
-
-  if (isStar(input)) return input;
-
-  return input
-    .split(",")
-    .map(parseETag);
-}