Add more test cases for prefer-string-raw rule (#2690)

Author: som-sm

test/prefer-string-raw.js

@@ -34,12 +34,16 @@ test.snapshot({
 		String.raw`import {} from "foo" with {"key\\key": "value"}`,
 		String.raw`export {} from "foo" with {key: "value\\value"}`,
 		String.raw`export {} from "foo" with {"key\\key": "value"}`,
+		String.raw`a = '\\'`,
+		String.raw`a = 'a\\b\"'`,
 	],
 	invalid: [
 		String.raw`a = 'a\\b'`,
 		String.raw`a = {['a\\b']: b}`,
 		String.raw`function a() {return'a\\b'}`,
 		String.raw`const foo = "foo \\x46";`,
+		String.raw`a = 'a\\b\''`,
+		String.raw`a = "a\\b\""`,
 	],
 });
 

test/snapshots/prefer-string-raw.js.md

@@ -87,3 +87,45 @@ Generated by [AVA](https://avajs.dev).
     > 1 | const foo = "foo \\\\x46";␊
         |             ^^^^^^^^^^^ \`String.raw\` should be used to avoid escaping \`\\\`.␊
     `
+
+## invalid(5): a = 'a\\b\''
+
+> Input
+
+    `␊
+      1 | a = 'a\\\\b\\''␊
+    `
+
+> Output
+
+    `␊
+      1 | a = String.raw\`a\\b'\`␊
+    `
+
+> Error 1/1
+
+    `␊
+    > 1 | a = 'a\\\\b\\''␊
+        |     ^^^^^^^^ \`String.raw\` should be used to avoid escaping \`\\\`.␊
+    `
+
+## invalid(6): a = "a\\b\""
+
+> Input
+
+    `␊
+      1 | a = "a\\\\b\\""␊
+    `
+
+> Output
+
+    `␊
+      1 | a = String.raw\`a\\b"\`␊
+    `
+
+> Error 1/1
+
+    `␊
+    > 1 | a = "a\\\\b\\""␊
+        |     ^^^^^^^^ \`String.raw\` should be used to avoid escaping \`\\\`.␊
+    `