From 1cdb2250e89d8344924c41873467b8219851c25e Mon Sep 17 00:00:00 2001 From: Ed Page Date: Wed, 27 Oct 2021 13:33:36 -0500 Subject: [PATCH] fix(derive): Define multiple policy for Special Types Before: - `bool`: a flag - `Option<_>`: not required - `Option>` is not required and when it is present, the value is not required - `Vec<_>`: multiple values, optional - `Option>`: multiple values, min values of 0, optional After: - `bool`: a flag - `Option<_>`: not required - `Option>` is not required and when it is present, the value is not required - `Vec<_>`: multiple occurrences, optional - optional: `Vec` implies 0 or more, so should not imply required - `Option>`: multiple occurrences, optional - optional: Use over `Vec` to detect when no option being present when using multiple values Motivations: My priorities were: 1. Are we getting in the users way? 2. Does the API make sense? 3. Does the API encourage best practices? I was originally concerned about the lack of composability with `Option>` and `Option>` (and eventually `Vec>`). It prescribes special meaning to each type depending on where it shows up, rather than providing a single meaning for a type generally. You then can't do things like have `Option<_>` mean "required argument with optional value" without hand constructing it. However, in practice the outer type correlates with the argument occurrence and the inner type with the value. It is rare to want the value behavior without also the occurrence behavior. So I figure it is probably fine as long as people can set the flags to manually get the behavior they want. `Vec<_>` implies multiple occurrences, rather than multiple values. Anecdotally, whenever I've used the old `Arg::multiple`, I thought I was getting `Arg::multiple_occurrences` only. `Arg::multiple_values`, without any bounds or delimiter requirement, can lead to a confusing user experience and isn't a good default for these. On top of that, if someone does have an unbounded or a delimiter multiple values, they are probably also using multiple occurrences. `Vec<_>` is optional because a `Vec` implies 0 or more, so we stick to the meaning of the rust type. At least for me, I also rarely need a required with multiple occurrences argument but more often need optional with multiple occurrences. `Option>` ends up matching `Vec<_>` which can raise the question of why have it. Some users might prefer the type. Otherwise, this is so users can detect whether the argument is present or not when using `min_values(0)`. Rather than defining an entire policy around this and having users customize it, or setting `min_values(0)` without the rest of a default policy, this gives people a blank slate to work from. Another design option would have been to not infer any special-type settings if someone sets a handful of settings manually, which would have avoided the confusion in Issue clap-rs/clap 2599 but I see that being confusing (for someone who knows the default, they will be expecting it to be additive; which flags disable inferred settings?) and brittle (as flags are added or changed, how do we ensure we keep this up?). Tests were added to ensure we support people customizing the behavior to match their needs. This is not solving: - `Vec>`, see clap-rs/clap 2924 - `(T1, T2)`, `Vec<(T1, T2)>`, etc, see clap-rs/clap 1717 - `Vec>` and many other potential combinations Fixes clap-rs/clap 1772 Fixes clap-rs/clap 2599 See also clap-rs/clap 2195 --- clap_derive/src/derives/args.rs | 6 +-- clap_derive/tests/arg_enum.rs | 8 +--- clap_derive/tests/options.rs | 66 +++++++++++++++++++++++++++++++-- 3 files changed, 66 insertions(+), 14 deletions(-) diff --git a/clap_derive/src/derives/args.rs b/clap_derive/src/derives/args.rs index da4be6b8..e513cbac 100644 --- a/clap_derive/src/derives/args.rs +++ b/clap_derive/src/derives/args.rs @@ -302,8 +302,7 @@ pub fn gen_augment( Ty::OptionVec => quote_spanned! { ty.span()=> .takes_value(true) .value_name(#value_name) - .multiple_values(true) - .min_values(0) + .multiple_occurrences(true) #possible_values #validator #allow_invalid_utf8 @@ -313,7 +312,7 @@ pub fn gen_augment( quote_spanned! { ty.span()=> .takes_value(true) .value_name(#value_name) - .multiple_values(true) + .multiple_occurrences(true) #possible_values #validator #allow_invalid_utf8 @@ -326,7 +325,6 @@ pub fn gen_augment( Ty::Other if flag => quote_spanned! { ty.span()=> .takes_value(false) - .multiple_values(false) }, Ty::Other => { diff --git a/clap_derive/tests/arg_enum.rs b/clap_derive/tests/arg_enum.rs index f5f0bfec..6f439919 100644 --- a/clap_derive/tests/arg_enum.rs +++ b/clap_derive/tests/arg_enum.rs @@ -419,7 +419,7 @@ fn vec_type() { Opt { arg: vec![ArgChoice::Foo, ArgChoice::Bar] }, - Opt::try_parse_from(&["", "-a", "foo", "bar"]).unwrap() + Opt::try_parse_from(&["", "-a", "foo", "-a", "bar"]).unwrap() ); assert!(Opt::try_parse_from(&["", "-a", "fOo"]).is_err()); } @@ -439,10 +439,6 @@ fn option_vec_type() { } assert_eq!(Opt { arg: None }, Opt::try_parse_from(&[""]).unwrap()); - assert_eq!( - Opt { arg: Some(vec![]) }, - Opt::try_parse_from(&["", "-a"]).unwrap() - ); assert_eq!( Opt { arg: Some(vec![ArgChoice::Foo]) @@ -453,7 +449,7 @@ fn option_vec_type() { Opt { arg: Some(vec![ArgChoice::Foo, ArgChoice::Bar]) }, - Opt::try_parse_from(&["", "-a", "foo", "bar"]).unwrap() + Opt::try_parse_from(&["", "-a", "foo", "-a", "bar"]).unwrap() ); assert!(Opt::try_parse_from(&["", "-a", "fOo"]).is_err()); } diff --git a/clap_derive/tests/options.rs b/clap_derive/tests/options.rs index 3ee40d2c..43fece81 100644 --- a/clap_derive/tests/options.rs +++ b/clap_derive/tests/options.rs @@ -259,7 +259,7 @@ fn two_option_option_types() { } #[test] -fn vec_type_is_multiple_values() { +fn vec_type_is_multiple_occurrences() { #[derive(Parser, PartialEq, Debug)] struct Opt { #[clap(short, long)] @@ -270,6 +270,42 @@ fn vec_type_is_multiple_values() { Opt::try_parse_from(&["test", "-a24"]).unwrap() ); assert_eq!(Opt { arg: vec![] }, Opt::try_parse_from(&["test"]).unwrap()); + assert_eq!( + Opt { arg: vec![24, 42] }, + Opt::try_parse_from(&["test", "-a", "24", "-a", "42"]).unwrap() + ); +} + +#[test] +fn vec_type_with_required() { + #[derive(Parser, PartialEq, Debug)] + struct Opt { + #[clap(short, long, required = true)] + arg: Vec, + } + assert_eq!( + Opt { arg: vec![24] }, + Opt::try_parse_from(&["test", "-a24"]).unwrap() + ); + assert!(Opt::try_parse_from(&["test"]).is_err()); + assert_eq!( + Opt { arg: vec![24, 42] }, + Opt::try_parse_from(&["test", "-a", "24", "-a", "42"]).unwrap() + ); +} + +#[test] +fn vec_type_with_multiple_values_only() { + #[derive(Parser, PartialEq, Debug)] + struct Opt { + #[clap(short, long, multiple_values(true), multiple_occurrences(false))] + arg: Vec, + } + assert_eq!( + Opt { arg: vec![24] }, + Opt::try_parse_from(&["test", "-a24"]).unwrap() + ); + assert_eq!(Opt { arg: vec![] }, Opt::try_parse_from(&["test"]).unwrap()); assert_eq!( Opt { arg: vec![24, 42] }, Opt::try_parse_from(&["test", "-a", "24", "42"]).unwrap() @@ -308,6 +344,28 @@ fn option_vec_type() { Opt::try_parse_from(&["test", "-a", "1"]).unwrap() ); + assert_eq!( + Opt { + arg: Some(vec![1, 2]) + }, + Opt::try_parse_from(&["test", "-a", "1", "-a", "2"]).unwrap() + ); + + assert_eq!(Opt { arg: None }, Opt::try_parse_from(&["test"]).unwrap()); +} + +#[test] +fn option_vec_type_structopt_behavior() { + #[derive(Parser, PartialEq, Debug)] + struct Opt { + #[clap(short, long, multiple_values(true), min_values(0))] + arg: Option>, + } + assert_eq!( + Opt { arg: Some(vec![1]) }, + Opt::try_parse_from(&["test", "-a", "1"]).unwrap() + ); + assert_eq!( Opt { arg: Some(vec![1, 2]) @@ -337,9 +395,9 @@ fn two_option_vec_types() { assert_eq!( Opt { arg: Some(vec![1]), - b: Some(vec![]) + b: None, }, - Opt::try_parse_from(&["test", "-a", "1", "-b"]).unwrap() + Opt::try_parse_from(&["test", "-a", "1"]).unwrap() ); assert_eq!( @@ -355,7 +413,7 @@ fn two_option_vec_types() { arg: Some(vec![1, 2]), b: Some(vec![1, 2]) }, - Opt::try_parse_from(&["test", "-a", "1", "2", "-b", "1", "2"]).unwrap() + Opt::try_parse_from(&["test", "-a", "1", "-a", "2", "-b", "1", "-b", "2"]).unwrap() ); assert_eq!(