{
  "$type": "site.standard.document",
  "bskyPostRef": {
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    "uri": "at://did:plc:ivbknywyskln22er3nkssdhl/app.bsky.feed.post/3mibvrewszam2"
  },
  "path": "/t/change-error-message-of-a-failing-assert-eq/24118#post_7",
  "publishedAt": "2026-03-30T14:38:50.000Z",
  "site": "https://internals.rust-lang.org",
  "tags": [
    "googletest - Rust",
    "assert_that!",
    "matches_pattern!",
    "non-fatal assertions"
  ],
  "textContent": "It's worth checking out the design of googletest - Rust which uses matcher expressions to make it more obvious that the right side is the expected value (e.g. assert_that! documentation) and also it has advanced matchers that provide more detailed error messages, printing subexpressions wherever `Debug` is implemented (matches_pattern!). It also adds its own test runner that you may optionally use to support tests that use`Result` for failures instead of panic-based assertions or support non-fatal assertions to be able to see multiple failures instead of stopping at the first.",
  "title": "Change error message of a failing `assert_eq!`"
}