test: expand extractPlaceholders tests (#413)

Author: mnahkies

packages/openapi-code-generator/src/core/openapi-utils.spec.ts

@@ -58,6 +58,70 @@ describe("core/openapi-utils", () => {
       ])
     })
 
-    // todo: expand tests for special characters / escaping
+    it("handles special characters in placeholder names", () => {
+      // template-expression-param-name = 1*( %x00-7A / %x7C / %x7E-10FFFF )
+      // essentially everything except { and }
+
+      const specialNames = [
+        "id:with-colon",
+        "id@with-at",
+        "id.with-dot",
+        "id_with-underscore",
+        "id~with-tilde",
+        "id!with-bang",
+        "id$with-dollar",
+        "id&with-ampersand",
+        "id'with-quote",
+        "id(with-parens)",
+        "id*with-asterisk",
+        "id+with-plus",
+        "id,with-comma",
+        "id;with-semicolon",
+        "id=with-equals",
+        "id%20with-percent",
+        "id中文", // Unicode
+      ]
+
+      for (const name of specialNames) {
+        expect(extractPlaceholders(`/{${name}}`)).toStrictEqual([
+          {
+            placeholder: name,
+            wholeString: `{${name}}`,
+          },
+        ])
+      }
+    })
+
+    it("handles /, ?, and # in placeholder names as per ABNF", () => {
+      // although these are forbidden in parameter values, the ABNF for the name allows them
+      const names = ["name/with/slash", "name?with?question", "name#with#hash"]
+
+      for (const name of names) {
+        expect(extractPlaceholders(`/{${name}}`)).toStrictEqual([
+          {
+            placeholder: name,
+            wholeString: `{${name}}`,
+          },
+        ])
+      }
+    })
+
+    it("does not extract empty placeholders", () => {
+      // template-expression-param-name = 1*...
+      expect(extractPlaceholders("/{}")).toStrictEqual([])
+    })
+
+    it("handles multiple placeholders in a single path segment", () => {
+      expect(extractPlaceholders("/{foo}{bar}")).toStrictEqual([
+        {placeholder: "foo", wholeString: "{foo}"},
+        {placeholder: "bar", wholeString: "{bar}"},
+      ])
+    })
+
+    it("handles placeholders mixed with literals in a single path segment", () => {
+      expect(extractPlaceholders("/prefix{foo}suffix")).toStrictEqual([
+        {placeholder: "foo", wholeString: "{foo}"},
+      ])
+    })
   })
 })

packages/openapi-code-generator/src/core/openapi-utils.ts

@@ -19,6 +19,10 @@ export function getNameFromRef({$ref}: Reference, prefix: string): string {
   return prefix + name.replace(/[-.]+/g, "_")
 }
 
+/**
+ * Given an openapi path template, extract the variable placeholders
+ * ref: {@link https://spec.openapis.org/oas/v3.2.0.html#path-templating path-templating}
+ */
 export function extractPlaceholders(
   it: string,
 ): {wholeString: string; placeholder: string | undefined}[] {