Report the member name instead of the signature in deprecation suggestions

[GON (gonappuccino)]

Fixes #62396

When a deprecated method is called on something that is not a plain name, such as object().passthrough(), this.m(), x["m"]() or (x.m)(), the suggestion showed the signature instead of the name: '(): Schema' is deprecated.

tryGetPropertyAccessOrIdentifierToString returns nothing for these receivers. As suggested in the review on #62406, checkDeprecatedSignature now skips parentheses around the callee and falls back to the member name (Name() for property accesses, including #private ones; GetElementOrPropertyAccessName for literal bracket accesses), giving The signature '(): Schema' of 'passthrough' is deprecated. Calls that already had a name are unchanged.

The issue is locked, so I could not comment there first.

Testing

New fourslash test deprecatedSignatureMemberName_test.go covers object().passthrough(), object()["passthrough"](), (object().passthrough)(), this.m() and this.#p(); all five fail without the change and pass with it.

AI disclosure

I used an AI assistant (Claude, Opus 5.5) to investigate, draft the change and test, and review them. I've read and understand the change and will handle the review myself.

[GON (gonappuccino)]

@microsoft-github-policy-service agree

[Copilot]

Copilot review overview

🟡 Changes recommended

The fallback excludes private method names such as this.#m().

Get a fresh assessment by requesting another Copilot review.

Review effort: Balanced
Findings: 1

Open (1)

• Include private names in deprecated member-call diagnostics · New

What changed in this PR

Improves deprecation suggestions by reporting member names when full access paths are unavailable.

Changes:

• Adds member-name fallback logic for access expressions.
• Adds fourslash coverage for call, bracket, and this receivers.

File	Description
tsc/​internal/​checker/​checker.go	Extracts member names for deprecation diagnostics.
tsc/​internal/​fourslash/​tests/​deprecatedSignatureMemberName_test.go	Verifies updated diagnostics.

---

💡 Add a code-review agent skill for context-aware, tailored reviews. Learn more in the docs.

[Copilot]

Copilot review overview

🔵 Needs a closer look

Parenthesized member callees still produce the signature-only diagnostic.

Review effort: Balanced
Findings: None

Resolved since last review (1)

• Include private names in deprecated member-call diagnostics

Previously missed (1)

In code that hasn't changed since last review

Unwrap parenthesized member callees before extracting the name

tsc/​internal/​checker/​checker.go:8542

Parenthesized member callees still fall back to the signature-only diagnostic. For example, (object().passthrough)() makes GetInvokedExpression return a ParenthesizedExpression, so neither this helper nor the new access-expression switch reaches passthrough. Unwrap parentheses before extracting the name, as getDeprecatedSuggestionNode already does.

[Copilot]

Copilot review overview

🟢 Approval recommended

The focused implementation handles the reported cases and includes comprehensive regression coverage.

Review effort: Balanced
Findings: None