dialyzer-analysis

Dialyzer static analysis identifies type and spec issues in Elixir and Erlang code. Add @spec annotations to functions, run `mix dialyzer`, then review warnings for pattern-match gaps, unmatched returns, and type mismatches. Fix by refining specs, handling union types correctly, and ensuring functions match their declared signatures.

Common warnings include no-return functions, unmatched returns, unknown functions, and pattern-match coverage gaps. Resolve by adding missing @spec definitions, verifying function existence and arity, handling edge cases in pattern matching, and correctly defining union and opaque types per success typing principles.

No. Dialyzer performs success typing inference without explicit specs, but @spec annotations improve coverage and catch more issues. Adding specs to public functions and complex internal functions yields the most value; gradual adoption is supported.

Define opaque types with @opaque in your module and reference remote types using the `module.type()` syntax. Dialyzer enforces that opaque types are only constructed and destructed through their defining module's functions, preventing invalid type operations across modules.

Yes. Dialyzer analyzes both Erlang and Elixir code. Apply the same @spec and @type patterns in Erlang using module attributes, run analysis across your codebase, and incrementally fix warnings following the same success typing and type consistency principles.

Unknown function warnings occur when Dialyzer cannot locate a function definition or its spec. Verify the function exists, check module name and arity, ensure dependencies are dialyzed, and add missing @spec declarations. Use a .plt file to cache precompiled type information for dependencies.