Implement Mapping::get_or_use

[collinc97]

Overview

let current_amount: u64 = Mapping::get_or_use(account, receiver, 0u64);

Closed Issues

Closes #2412

[codecov]

Codecov Report

Merging #2413 (1fc1cc1) into testnet3 (bb73b9f) will increase coverage by 0.02%.
The diff coverage is n/a.

@@             Coverage Diff              @@
##           testnet3    #2413      +/-   ##
============================================
+ Coverage     78.59%   78.61%   +0.02%     
============================================
  Files           154      154              
  Lines          4709     4710       +1     
  Branches       4708     4709       +1     
============================================
+ Hits           3701     3703       +2     
+ Misses         1008     1007       -1     

Impacted Files	Coverage Δ
compiler/ast/src/functions/core_function.rs	100.00% <ø> (ø)
compiler/ast/src/lib.rs	79.48% <ø> (ø)
compiler/parser/src/parser/expression.rs	83.77% <ø> (ø)
compiler/parser/src/parser/statement.rs	83.50% <ø> (ø)
...er/passes/src/code_generation/visit_expressions.rs	82.25% <ø> (ø)
.../src/dead_code_elimination/eliminate_expression.rs	71.42% <ø> (ø)
compiler/passes/src/type_checking/checker.rs	95.83% <ø> (ø)
compiler/span/src/symbol.rs	84.61% <ø> (ø)

... and 5 files with indirect coverage changes

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[d0cd]

PR looks good!
Left some minor points to address.

[d0cd]

We should delete this file

[d0cd]

We should delete this file

[d0cd]

LGTM!