add InetAddr constructor from string

NEWS.md

@@ -81,6 +81,11 @@ Standard library changes
 
 * `quantile` now accepts in all cases collections whose `eltype` is not a subtype of `Number` ([#30938]).
 
+#### Sockets
+
+* Added `InetAddr` constructor from `AbstractString`, representing IP address, and `Integer`,
+  representing port number ([#31459]).
+
 #### Miscellaneous
 
 * Since environment variables on Windows are case-insensitive, `ENV` now converts its keys

stdlib/Sockets/src/IPAddr.jl

@@ -271,7 +271,35 @@ struct InetAddr{T<:IPAddr}
     port::UInt16
 end
 
+"""
+    InetAddr(ip::IPAddr, port) -> InetAddr
+
+Returns an InetAddr object from ip address `ip` and port number `port`.
+
+# Examples
+```jldoctest
+julia> Sockets.InetAddr(ip"127.0.0.1", 8000)
+Sockets.InetAddr{IPv4}(ip"127.0.0.1", 8000)
+```
+"""
 InetAddr(ip::IPAddr, port) = InetAddr{typeof(ip)}(ip, port)
+
+"""
+    InetAddr(str::AbstractString, port) -> InetAddr
+
+Returns an InetAddr object from ip address `str` formatted as [`AbstractString`](@ref)
+and port number `port`.
+
+!!! compat "Julia 1.2"
+    constructor from `AbstractString` requires at least Julia 1.2.
+
+# Examples
+```jldoctest
+julia> Sockets.InetAddr("127.0.0.1", 8000)
+Sockets.InetAddr{IPv4}(ip"127.0.0.1", 8000)
+```
+"""
+InetAddr(str::AbstractString, port) = InetAddr(parse(IPAddr, str), port)
 function show(io::IO, addr::InetAddr)
     show(io, typeof(addr))
     print(io, "(")

stdlib/Sockets/test/runtests.jl

@@ -66,6 +66,9 @@ end
     @test inet.port == 1024
     str = "Sockets.InetAddr{$(isdefined(Main, :IPv4) ? "" : "Sockets.")IPv4}(ip\"127.0.0.1\", 1024)"
     @test sprint(show, inet) == str
+    inet = Sockets.InetAddr("127.0.0.1", 1024)
+    @test inet.host == ip"127.0.0.1"
+    @test inet.port == 1024
 end
 @testset "InetAddr invalid port" begin
     @test_throws InexactError Sockets.InetAddr(IPv4(127,0,0,1), -1)