fix: add context-aware SPDX and pragma completions

[rifuki]

Closes #223

Problem

Completion inside source-unit directive contexts can fall through to normal/global Solidity completions. This makes early SPDX and pragma typing noisy, and SPDX insertion can duplicate the existing // prefix depending on the client.

Fix

• Detect SPDX directive prefixes such as // S, // SP, // SPD, and // SPDX.
• Offer full SPDX license directive lines using a line replacement edit.
• Add pragma completions for pragma , pragma solidity , and pragma abicoder contexts.
• Suppress unrelated generic/global completions in those directive contexts.

Tests

• rustfmt src/completion.rs tests/completion.rs
• cargo check
• cargo test --test completion -- --nocapture
• cargo test --lib -- --nocapture
• cargo test
• cargo build --release --bin solidity-language-server
• git diff --check

[mmsaki]

Looks like you need to specify the start and end to replace if we need the version completions.

pragma solidity 0.*| ^0.8.35;
//                 ^ completion cursor

[rifuki]

Fixed in 6a4663e. Version completions now use a text edit from the start of the pragma solidity value through the end of the existing version expression before ;. So the example pragma solidity 0.*| ^0.8.35; is replaced as a whole value and becomes pragma solidity ^0.8.35;, instead of inserting at the cursor or duplicating the trailing text.

Added test_context_completion_pragma_solidity_version_replaces_partial_token for this exact shape.

Verified with:

cargo check
cargo test --test completion test_context_completion
cargo test --test completion
cargo test