Indent string diffs lines (#2648)

I noticed that the failure messages are a little easier to read if the
lines showing the point in the string that deviates are indented
relative to the "Which" header.

Before

    Expected: a String that:
      equals 'some other String'
    Actual: 'some String'
    Which: differs at offset 5:
    some other Stri ...
    some String
         ^

After

    Expected: a String that:
      equals 'some other String'
    Actual: 'some String'
    Which: differs at offset 5:
      some other Stri ...
      some String
           ^
3 files changed
tree: 68327bde069eebe6713e1d0a2126753d86819d9b
  1. .github/
  2. integration_tests/
  3. pkgs/
  4. tool/
  5. .gitattributes
  6. .gitignore
  7. analysis_options.yaml
  8. CODEOWNERS
  9. CONTRIBUTING.md
  10. mono_repo.yaml
  11. pubspec.yaml
  12. README.md
README.md

Dart CI OpenSSF Scorecard

What's here?

Welcome! package:test is the standard testing library for Dart and Flutter. If you have questions about Dart testing, please see the docs for package:test. package:test_api and package:test_core are implementation details and generally not user-facing.

package:checks is a relatively new library for expressing test expectations. It's a more modern version of package:matcher and features a literate API.

Packages

PackageDescriptionIssuesVersion
checksA framework for checking values against expectations and building custom expectations.issuespub package
fake_asyncFake asynchronous events such as timers and microtasks for deterministic testing.issuespub package
matcherSupport for specifying test expectations via an extensible Matcher class. Also includes a number of built-in Matcher implementations for common cases.issuespub package
testA full featured library for writing and running Dart tests across platforms.issuespub package
test_apiThe user facing API for structuring Dart tests and checking expectations.pub package
test_coreA basic library for writing tests and running them on the VM.pub package
test_descriptorAn API for defining and verifying files and directory structures.issuespub package
test_processTest processes: starting; validating stdout and stderr; checking exit code.issuespub package