feat(inlay-hints): don't show inlay hints in some cases

server/src/e2e/suite/testcases/inlayHints/calls.test

@@ -40,7 +40,7 @@ fun foo(bar: Int) {}
 struct Bar { bar: Int/*  as int257 */ }
 
 fun test() {
-    let instance/* : Bar */ = Bar { bar: 10 };
+    let instance = Bar { bar: 10 };
     foo(instance.bar); // no hint here
 }
 

server/src/e2e/suite/testcases/inlayHints/contract.test

@@ -111,43 +111,21 @@ contract Foo {
 Show parameter name hints in function calls
 ========================================================================
 contract Foo {
-
-    internal fun test1(x: Int) {
-        return x;
-    }
-
-    external fun test2(x: Int) {
-        return x;
-    }
-
-    get fun test3(x: Int) {
-        return x;
+    get fun test1(value: Int) {
+        return value;
     }
 
     init() {
         const a = self.test1(42);
-        const b = self.test2(42);
-        const c = self.test3(42);
     }
 }
 ------------------------------------------------------------------------
 contract Foo {
-
-    internal fun test1(x: Int) {
-        return x;
-    }
-
-    external fun test2(x: Int) {
-        return x;
-    }
-
-    get/* (0x1091c) */ fun test3(x: Int) {
-        return x;
+    get/* (0x1c89d) */ fun test1(value: Int) {
+        return value;
     }
 
     init() {
-        const a = self.test1(/* x: */42);
-        const b = self.test2(/* x: */42);
-        const c = self.test3(/* x: */42);
+        const a = self.test1(/* value: */42);
     }
 }

server/src/e2e/suite/testcases/inlayHints/initOf.test

@@ -66,3 +66,26 @@ contract Counter {
         initOf Counter(/* some: */10, /* other: */"hello");
     }
 }
+
+========================================================================
+initOf with single letter parameter
+========================================================================
+primitive Int;
+
+contract Counter {
+    init(s: Int) {}
+
+    fun test() {
+        initOf Counter(10);
+    }
+}
+------------------------------------------------------------------------
+primitive Int;
+
+contract Counter {
+    init(s: Int) {}
+
+    fun test() {
+        initOf Counter(10);
+    }
+}

server/src/e2e/suite/testcases/inlayHints/parameters.test

@@ -0,0 +1,18 @@
+========================================================================
+Single letter parameter
+========================================================================
+primitive Int;
+
+fun foo(a: int, b: Int) {}
+
+fun test() {
+    foo(1, 2);
+}
+------------------------------------------------------------------------
+primitive Int;
+
+fun foo(a: int, b: Int) {}
+
+fun test() {
+    foo(1, 2);
+}

server/src/e2e/suite/testcases/inlayHints/variables.test

@@ -31,3 +31,22 @@ fun foo() {
     let a: map<Int, String> = emptyMap();
     foreach (key/* : Int */, value/* : String */ in a) {}
 }
+
+========================================================================
+Local variable initialized with struct init
+========================================================================
+primitive Int;
+
+struct Foo { value: Int }
+
+fun foo() {
+    let a = Foo { value: 10 };
+}
+------------------------------------------------------------------------
+primitive Int;
+
+struct Foo { value: Int/*  as int257 */ }
+
+fun foo() {
+    let a = Foo { value: 10 };
+}

server/src/inlays/collect.ts

@@ -21,6 +21,11 @@ function processParameterHints(
         const arg = args[i]
         const paramName = param.name()
 
+        if (paramName.length === 1) {
+            // don't show hints for single letter parameters
+            continue
+        }
+
         if (arg.text === paramName || arg.text.endsWith(`.${paramName}`)) {
             // no need to add hint for `takeFoo(foo)` or `takeFoo(val.foo)`
             continue
@@ -93,6 +98,10 @@ export function collect(
             const expr = decl.value()
             if (!expr) return true
 
+            // don't show hint for:
+            // let params = SomeParams{}
+            if (expr.node.type === "instance_expression") return true
+
             const name = decl.nameIdentifier()
             if (!name) return true