feat(getStaticValue): allow RegExp getters (#77)

Co-authored-by: Yosuke Ota <[email protected]>

Author: RunDevelopment

src/get-static-value.mjs

@@ -170,6 +170,24 @@ const callPassThrough = new Set([
     Object.seal,
 ])
 
+/** @type {ReadonlyArray<readonly [Function, ReadonlySet<string>]>} */
+const getterAllowed = [
+    [
+        RegExp,
+        new Set([
+            "dotAll",
+            "flags",
+            "global",
+            "hasIndices",
+            "ignoreCase",
+            "multiline",
+            "source",
+            "sticky",
+            "unicode",
+        ]),
+    ],
+]
+
 /**
  * Get the property descriptor.
  * @param {object} object The object to get.
@@ -438,8 +456,19 @@ const operations = Object.freeze({
             }
             const property = getStaticPropertyNameValue(node, initialScope)
 
-            if (property != null && !isGetter(object.value, property.value)) {
-                return { value: object.value[property.value] }
+            if (property != null) {
+                if (!isGetter(object.value, property.value)) {
+                    return { value: object.value[property.value] }
+                }
+
+                for (const [classFn, allowed] of getterAllowed) {
+                    if (
+                        object.value instanceof classFn &&
+                        allowed.has(property.value)
+                    ) {
+                        return { value: object.value[property.value] }
+                    }
+                }
             }
         }
         return null

test/get-static-value.mjs

@@ -9,6 +9,8 @@ describe("The 'getStaticValue' function", () => {
         { code: "[1, 2, 3]", expected: { value: [1, 2, 3] } },
         { code: "[,, 3]", expected: { value: [, , 3] } }, //eslint-disable-line no-sparse-arrays
         { code: "[1, ...[2, 3]]", expected: { value: [1, 2, 3] } },
+        { code: "[1, ...[2, 3]].length", expected: { value: 3 } },
+        { code: "[1, ...[2, 3]]['1']", expected: { value: 2 } },
         { code: "[0, a]", expected: null },
         { code: "[0, ...a]", expected: null },
         { code: "a = 1 + 2", expected: { value: 3 } },
@@ -74,6 +76,14 @@ describe("The 'getStaticValue' function", () => {
         { code: "1", expected: { value: 1 } },
         { code: "'hello'", expected: { value: "hello" } },
         { code: "/foo/gu", expected: { value: /foo/gu } },
+        { code: "RegExp(/foo/gu)", expected: { value: /foo/gu } },
+        { code: "RegExp(/foo/, 'gu')", expected: { value: /foo/gu } },
+        { code: "RegExp('foo', 'gu')", expected: { value: /foo/gu } },
+        { code: "new RegExp('foo', 'gu')", expected: { value: /foo/gu } },
+        { code: "/foo/gu.source", expected: { value: "foo" } },
+        { code: "/foo/gu.flags", expected: { value: "gu" } },
+        { code: "/foo/gu.unicode", expected: { value: true } },
+        { code: "/foo/gu.ignoreCase", expected: { value: false } },
         { code: "true && 1", expected: { value: 1 } },
         { code: "false && a", expected: { value: false } },
         { code: "true || a", expected: { value: true } },
@@ -160,6 +170,8 @@ describe("The 'getStaticValue' function", () => {
         { code: "String.raw`\\unicode`", expected: { value: "\\unicode" } },
         { code: "`he${a}o`", expected: null }, //eslint-disable-line no-template-curly-in-string
         { code: "x`hello`", expected: null },
+        { code: "'abc'.length", expected: { value: 3 } },
+        { code: "'abc'[1]", expected: { value: "b" } },
         { code: "'  foo  '.trim()", expected: { value: "foo" } },
         { code: "'  foo  '.trim().toUpperCase()", expected: { value: "FOO" } },
         { code: "'  foo  '.indexOf('f')", expected: { value: 2 } },