gopls/internal/test/marker: add reproducers for moveparam bug bash bugs

Add a marker test that reproduces bugs encountered during bug bash of
parameter movement refactoring. Subsequent CLs will fix these bugs.

For golang/go#70599

Change-Id: Ieb52c1c02f11fa22bc043d7793509914d76d27ca
Reviewed-on: https://go-review.googlesource.com/c/tools/+/632115
Reviewed-by: Alan Donovan <[email protected]>
LUCI-TryBot-Result: Go LUCI <[email protected]>

Author: findleyr

gopls/internal/test/marker/testdata/codeaction/moveparam_issue70599.txt

@@ -0,0 +1,102 @@
+This test reproduces various bugs encountered while bug-bashing on the movement
+refactoring.
+
+TODO(rfindley): fix these bugs.
+
+-- go.mod --
+module example.com
+
+go 1.21
+
+-- unnecessaryconversion.go --
+package a
+
+// We should not add unnecessary conversions to concrete arguments to concrete
+// parameters when the parameter use is in assignment context.
+
+type Hash [32]byte
+
+func Cache(key [32]byte, value any) { //@codeaction("key", "refactor.rewrite.moveParamRight", result=conversion)
+	// Not implemented.
+}
+
+func _() {
+	var k Hash
+	Cache(k, 0)
+	Cache(Hash{}, 1)
+	Cache([32]byte{}, 2)
+}
+
+-- @conversion/unnecessaryconversion.go --
+package a
+
+// We should not add unnecessary conversions to concrete arguments to concrete
+// parameters when the parameter use is in assignment context.
+
+type Hash [32]byte
+
+func Cache(value any, key [32]byte) { //@codeaction("key", "refactor.rewrite.moveParamRight", result=conversion)
+	// Not implemented.
+}
+
+func _() {
+	var k Hash
+	Cache(0, [32]byte(k))
+	Cache(1, [32]byte(Hash{}))
+	Cache(2, [32]byte{})
+}
+-- shortvardecl.go --
+package a
+
+func Short(x, y int) (int, int) { //@codeaction("x", "refactor.rewrite.moveParamRight", result=short)
+	return x, y
+}
+
+func _() {
+	x, y := Short(0, 1)
+	_, _ = x, y
+}
+
+func _() {
+	var x, y int
+	x, y = Short(0, 1)
+	_, _ = x, y
+}
+
+func _() {
+	_, _ = Short(0, 1)
+}
+-- @short/shortvardecl.go --
+package a
+
+func Short(y, x int) (int, int) { //@codeaction("x", "refactor.rewrite.moveParamRight", result=short)
+	return x, y
+}
+
+func _() {
+	var x, y int
+	x, y = Short(1, 0)
+	_, _ = x, y
+}
+
+func _() {
+	var x, y int
+	x, y = Short(1, 0)
+	_, _ = x, y
+}
+
+func _() {
+	_, _ = Short(1, 0)
+}
+-- variadic.go --
+package a
+
+// We should not offer movement involving variadic parameters if it is not well
+// supported.
+
+func Variadic(x int, y ...string) { //@codeaction("x", "refactor.rewrite.moveParamRight", err="type checking rewritten package")
+}
+
+func _() {
+	Variadic(1, "a", "b")
+}