feat!: output pure ESM for .mjs files

[eduardoboucas]

Summary

Currently, ESM functions are transpiled down to CommonJS. With this PR, we'll output pure ESM functions when:

• The input function file has the .mjs extension, and
• The zisi_pure_esm_mjs feature flag is on

Part of #750.

[github-actions]

⏱ Benchmark results

Comparing with e15da2c

largeDepsEsbuild: 8.4s

⬆️ 13.71% increase vs. e15da2c

^                                   8.5s                                                            8.4s  
│                                   ┌──┐                            8.2s                            ┌──┐  
│                                   |  |                            ┌──┐                            |▒▒|  
│   7.1s                            |  |            7.1s            |  |                    7.3s    |▒▒|  
│ ──┌──┐────6.9s────────────────────┼──┼────────────┌──┐────6.9s────┼──┼────────────────────┌──┐────|▒▒|──
│   |  |    ┌──┐    6.4s            |  |    6.5s    |  |    ┌──┐    |  |            6.2s    |  |    |▒▒|  
│   |  |    |  |    ┌──┐     6s     |  |    ┌──┐    |  |    |  |    |  |    5.9s    ┌──┐    |  |    |▒▒|  
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│   |  |    |  |    |  |    |  |    |  |    |  |    |  |    |  |    |  |    |  |    |  |    |  |    |▒▒|  
└───┴──┴────┴──┴────┴──┴────┴──┴────┴──┴────┴──┴────┴──┴────┴──┴────┴──┴────┴──┴────┴──┴────┴──┴────┴──┴──>
    T-12    T-11    T-10    T-9     T-8     T-7     T-6     T-5     T-4     T-3     T-2     T-1      T    

Legend

• T-15 (344f4ae): 6.6s
• T-14 (e1200a2): 6.1s
• T-13 (850404d): 6s
• T-12 (b472a84): 7.1s
• T-11 (dbc0857): 6.9s
• T-10 (4a49aca): 6.4s
• T-9 (66a3e37): 6s
• T-8 (e86b551): 8.5s
• T-7 (5e82e17): 6.5s
• T-6 (62b98f6): 7.1s
• T-5 (fda6fdd): 6.9s
• T-4 (75f5d1e): 8.2s
• T-3 (447ad3b): 5.9s
• T-2 (d8d9e38): 6.2s
• T-1 (e15da2c): 7.3s
• T (current commit): 8.4s

largeDepsNft: 44.2s

⬆️ 20.77% increase vs. e15da2c

^                                  46.8s                                                                  
│                                   ┌──┐                            44s                            44.2s  
│                                   |  |                            ┌──┐                            ┌──┐  
│                                   |  |                            |  |                            |▒▒|  
│                                   |  |                            |  |                            |▒▒|  
│  35.5s   34.4s                    |  |           35.4s            |  |                    35s     |▒▒|  
│ ──┌──┐────┌──┐────────────────────┼──┼───32.3s────┌──┐────────────┼──┼────────────────────┌──┐────|▒▒|──
│   |  |    |  |    30s    29.9s    |  |    ┌──┐    |  |            |  |           29.5s    |  |    |▒▒|  
│   |  |    |  |    ┌──┐    ┌──┐    |  |    |  |    |  |            |  |   27.2s    ┌──┐    |  |    |▒▒|  
│   |  |    |  |    |  |    |  |    |  |    |  |    |  |            |  |    ┌──┐    |  |    |  |    |▒▒|  
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│   |  |    |  |    |  |    |  |    |  |    |  |    |  |            |  |    |  |    |  |    |  |    |▒▒|  
│   |  |    |  |    |  |    |  |    |  |    |  |    |  |    n/a     |  |    |  |    |  |    |  |    |▒▒|  
└───┴──┴────┴──┴────┴──┴────┴──┴────┴──┴────┴──┴────┴──┴────────────┴──┴────┴──┴────┴──┴────┴──┴────┴──┴──>
    T-12    T-11    T-10    T-9     T-8     T-7     T-6     T-5     T-4     T-3     T-2     T-1      T    

Legend

• T-15 (344f4ae): 30.7s
• T-14 (e1200a2): n/a
• T-13 (850404d): 27.6s
• T-12 (b472a84): 35.5s
• T-11 (dbc0857): 34.4s
• T-10 (4a49aca): 30s
• T-9 (66a3e37): 29.9s
• T-8 (e86b551): 46.8s
• T-7 (5e82e17): 32.3s
• T-6 (62b98f6): 35.4s
• T-5 (fda6fdd): n/a
• T-4 (75f5d1e): 44s
• T-3 (447ad3b): 27.2s
• T-2 (d8d9e38): 29.5s
• T-1 (e15da2c): 35s
• T (current commit): 44.2s

largeDepsZisi: 1m 0.2s

⬆️ 10.75% increase vs. e15da2c

^                                 1m 4.3s                                                                 
│                                   ┌──┐                                                          1m 0.2s 
│                                   |  |                           59.4s                            ┌──┐  
│  53.1s                            |  |           54.4s            ┌──┐                   53.7s    |▒▒|  
│   ┌──┐   52.9s                    |  |            ┌──┐   51.1s    |  |                    ┌──┐    |▒▒|  
│ ──┼──┼────┌──┐────────────────────┼──┼───46.9s────┼──┼────┌──┐────┼──┼────────────────────┼──┼────|▒▒|──
│   |  |    |  |    45s    44.4s    |  |    ┌──┐    |  |    |  |    |  |           44.4s    |  |    |▒▒|  
│   |  |    |  |    ┌──┐    ┌──┐    |  |    |  |    |  |    |  |    |  |   41.7s    ┌──┐    |  |    |▒▒|  
│   |  |    |  |    |  |    |  |    |  |    |  |    |  |    |  |    |  |    ┌──┐    |  |    |  |    |▒▒|  
│   |  |    |  |    |  |    |  |    |  |    |  |    |  |    |  |    |  |    |  |    |  |    |  |    |▒▒|  
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│   |  |    |  |    |  |    |  |    |  |    |  |    |  |    |  |    |  |    |  |    |  |    |  |    |▒▒|  
│   |  |    |  |    |  |    |  |    |  |    |  |    |  |    |  |    |  |    |  |    |  |    |  |    |▒▒|  
│   |  |    |  |    |  |    |  |    |  |    |  |    |  |    |  |    |  |    |  |    |  |    |  |    |▒▒|  
│   |  |    |  |    |  |    |  |    |  |    |  |    |  |    |  |    |  |    |  |    |  |    |  |    |▒▒|  
└───┴──┴────┴──┴────┴──┴────┴──┴────┴──┴────┴──┴────┴──┴────┴──┴────┴──┴────┴──┴────┴──┴────┴──┴────┴──┴──>
    T-12    T-11    T-10    T-9     T-8     T-7     T-6     T-5     T-4     T-3     T-2     T-1      T    

Legend

• T-15 (344f4ae): 45.5s
• T-14 (e1200a2): 45.4s
• T-13 (850404d): 42.5s
• T-12 (b472a84): 53.1s
• T-11 (dbc0857): 52.9s
• T-10 (4a49aca): 45s
• T-9 (66a3e37): 44.4s
• T-8 (e86b551): 1m 4.3s
• T-7 (5e82e17): 46.9s
• T-6 (62b98f6): 54.4s
• T-5 (fda6fdd): 51.1s
• T-4 (75f5d1e): 59.4s
• T-3 (447ad3b): 41.7s
• T-2 (d8d9e38): 44.4s
• T-1 (e15da2c): 53.7s
• T (current commit): 1m 0.2s