From 6ce065ea395d355ef3b32099a7bdf70ecd998da1 Mon Sep 17 00:00:00 2001
From: Lars Kappert <lars@webpro.nl>
Date: Sun, 24 Mar 2024 10:50:38 +0100
Subject: [PATCH] Fix `pos` for computed props in class members (closes #360)

---
 packages/knip/fixtures/class-members/index.ts |  2 ++
 .../class-members/iterator-generator.ts       | 23 +++++++++++++++++++
 .../knip/fixtures/class-members/iterator.ts   | 10 ++++++++
 .../visitors/exports/exportKeyword.ts         |  3 ++-
 packages/knip/test/class-members.test.ts      | 14 ++++++-----
 5 files changed, 45 insertions(+), 7 deletions(-)
 create mode 100644 packages/knip/fixtures/class-members/iterator-generator.ts
 create mode 100644 packages/knip/fixtures/class-members/iterator.ts

diff --git a/packages/knip/fixtures/class-members/index.ts b/packages/knip/fixtures/class-members/index.ts
index 17b94da53..a3a838e20 100644
--- a/packages/knip/fixtures/class-members/index.ts
+++ b/packages/knip/fixtures/class-members/index.ts
@@ -1,4 +1,6 @@
 import { MyClass } from './members';
+import { AbstractClassGen, ExtendedClassGen } from './iterator-generator';
+import { AbstractClass, ExtendedClass } from './iterator';
 
 const instance = new MyClass();
 
diff --git a/packages/knip/fixtures/class-members/iterator-generator.ts b/packages/knip/fixtures/class-members/iterator-generator.ts
new file mode 100644
index 000000000..f1b16ee92
--- /dev/null
+++ b/packages/knip/fixtures/class-members/iterator-generator.ts
@@ -0,0 +1,23 @@
+export abstract class AbstractClassGen {
+  protected constructor() {}
+
+  public abstract implemented(): AbstractClassGen;
+
+  public abstract unimplemented(): AbstractClassGen;
+
+  public abstract [Symbol.iterator](): Iterator<AbstractClassGen>;
+}
+
+export class ExtendedClassGen extends AbstractClassGen {
+  public constructor() {
+    super();
+  }
+
+  public implemented(): AbstractClassGen {
+    return this;
+  }
+
+  public *[Symbol.iterator](): Iterator<AbstractClassGen> {
+    yield this;
+  }
+}
diff --git a/packages/knip/fixtures/class-members/iterator.ts b/packages/knip/fixtures/class-members/iterator.ts
new file mode 100644
index 000000000..46eb04cf9
--- /dev/null
+++ b/packages/knip/fixtures/class-members/iterator.ts
@@ -0,0 +1,10 @@
+export abstract class AbstractClass {
+  public abstract implemented(): AbstractClass;
+  public abstract [Symbol.toStringTag](): AbstractClass;
+}
+
+export class ExtendedClass extends AbstractClass {
+  public implemented(): AbstractClass {
+    return this;
+  }
+}
diff --git a/packages/knip/src/typescript/visitors/exports/exportKeyword.ts b/packages/knip/src/typescript/visitors/exports/exportKeyword.ts
index b33fd1cd4..46742cc13 100644
--- a/packages/knip/src/typescript/visitors/exports/exportKeyword.ts
+++ b/packages/knip/src/typescript/visitors/exports/exportKeyword.ts
@@ -97,7 +97,8 @@ export default visit(
               .map(member => ({
                 node: member,
                 identifier: member.name.getText(),
-                pos: member.name.getStart(),
+                // Naive, but [does.the.job()]
+                pos: member.name.getStart() + (ts.isComputedPropertyName(member.name) ? 1 : 0),
                 type: SymbolType.MEMBER,
                 fix: undefined,
               }))
diff --git a/packages/knip/test/class-members.test.ts b/packages/knip/test/class-members.test.ts
index 30023e644..765737960 100644
--- a/packages/knip/test/class-members.test.ts
+++ b/packages/knip/test/class-members.test.ts
@@ -14,6 +14,7 @@ test('Find unused class members', async () => {
   });
 
   assert.equal(Object.keys(issues.classMembers['members.ts']).length, 6);
+  assert(issues.classMembers['iterator-generator.ts']['unimplemented']);
   assert(issues.classMembers['members.ts']['bUnusedPublic']);
   assert(issues.classMembers['members.ts']['cUnusedProp']);
   assert(issues.classMembers['members.ts']['dUnusedMember']);
@@ -23,9 +24,9 @@ test('Find unused class members', async () => {
 
   assert.deepEqual(counters, {
     ...baseCounters,
-    classMembers: 6,
-    processed: 2,
-    total: 2,
+    classMembers: 7,
+    processed: 4,
+    total: 4,
   });
 });
 
@@ -37,6 +38,7 @@ test('Find unused class members (isIncludeEntryExports)', async () => {
   });
 
   assert.equal(Object.keys(issues.classMembers['members.ts']).length, 6);
+  assert(issues.classMembers['iterator-generator.ts']['unimplemented']);
   assert(issues.classMembers['index.ts']['unusedMemberInEntry']);
   assert(issues.classMembers['members.ts']['bUnusedPublic']);
   assert(issues.classMembers['members.ts']['cUnusedProp']);
@@ -47,8 +49,8 @@ test('Find unused class members (isIncludeEntryExports)', async () => {
 
   assert.deepEqual(counters, {
     ...baseCounters,
-    classMembers: 7,
-    processed: 2,
-    total: 2,
+    classMembers: 8,
+    processed: 4,
+    total: 4,
   });
 });