[cargo-nextest] add help text for --skip and --exact

Provide a hint to use a filter expression instead.

Closes #29.

cargo-nextest/src/dispatch.rs

@@ -456,6 +456,7 @@ impl TestBuildFilter {
         let mut ignore_filters = Vec::new();
         let mut read_trailing_filters = false;
 
+        let mut skip_exact = Vec::new();
         let mut unsupported_args = Vec::new();
 
         patterns.extend(
@@ -473,6 +474,9 @@ impl TestBuildFilter {
                     } else if s == "--" {
                         read_trailing_filters = true;
                         false
+                    } else if s == "--skip" || s == "--exact" {
+                        skip_exact.push(s.clone());
+                        false
                     } else {
                         unsupported_args.push(s.clone());
                         true
@@ -499,6 +503,13 @@ impl TestBuildFilter {
             }
         }
 
+        if !skip_exact.is_empty() {
+            return Err(ExpectedError::test_binary_args_parse_error(
+                "unsupported\n(hint: use a filter expression instead: <https://nexte.st/book/filter-expressions>)",
+                skip_exact,
+            ));
+        }
+
         if !unsupported_args.is_empty() {
             return Err(ExpectedError::test_binary_args_parse_error(
                 "unsupported",

site/src/book/running.md

@@ -40,6 +40,17 @@ cargo nextest run <test-name1> <test-name2>...
 
 This is different from `cargo test`, where you have to specify a `--`, for example: `cargo test -- <test-name1> <test-name2>...`.
 
+### `--skip` and `--exact`
+
+Nextest does not support `--skip` and `--exact` directly; instead, it supports more powerful [filter expressions](filter-expressions.md) which supersede these options.
+
+Here are some examples:
+
+|                Cargo test command               |                     Nextest command                     |
+|:-----------------------------------------------:|:-------------------------------------------------------:|
+| `cargo test -- --skip skip1 --skip skip2 test3` | `cargo nextest run -E 'test(test3) - test(/skip[12]/)'` |
+| `cargo test -- --exact test1 test2`             |   `cargo nextest run -E 'test(=test1) + test(=test2)'`  |
+
 ### Filtering by build platform
 
 While cross-compiling code, some tests (e.g. proc-macro tests) may need to be run on the host platform. To filter tests based on the build platform they're for, nextest accepts the `--platform-filter` option with values `target`, `host` or `any` (default).

site/src/book/usage.md

@@ -19,5 +19,4 @@ For more information about running tests, see [Running tests](running.md).
     To work around this, consider combining those tests into one so that nextest runs them as a
     unit, or excluding those tests from nextest.
 * There's [no way](https://github.com/nextest-rs/nextest/issues/28) to mark a particular test binary as excluded from nextest.
-* The `--skip` and `--exact` test filter options are currently [not supported](https://github.com/nextest-rs/nextest/issues/29) by nextest.
 * Doctests are currently [not supported](https://github.com/nextest-rs/nextest/issues/16) because of limitations in stable Rust. Locally and in CI, after `cargo nextest run`, use `cargo test --doc` to run all doctests.