Background/Situation

Sometimes, code completion suggests inappropriate default or incorrect expected order. The support/dev team might want detailed info about the completion ranking dump. Usually, the IDEs' log find didn't contain details about this.

Question

How to dump code completion ranking and save it?

Answer

There is an IDE's internal action named Dump Lookup Element Weights to Log, which requires enabling the IDE's Internal mode first. However, this action must be called when the completion popup is visible, so you can only invoke this by using the keyboard, so pressing Ctrl+Alt+Shift+W(⌥⇧⌘W on macOS) when the completion popup is on the screen, pasting the clipboard content to a text editor will save it.

This applies to all JetBrains IDEs such as IDEA, WebStorm, etc.

The final output might be like this:

selected: super
prefix: s
weights:
super	frozen=true, sorter=1, stats=0, explicitProximity=0, proximity=[accessibility=NORMAL, referenceList=unknown, samePsiMember=0, explicitlyImported=UNKNOWN, javaInheritance=false, groovyReferenceListWeigher=unknown, openedInEditor=false, sameDirectory=false, sameLogicalRoot=false, sameModule=0, kotlin.preferKotlinx=null, knownElement=0, inResolveScope=false, directoryType=0, sdkOrLibrary=false], ml_weigh=[java_keyword_name=super,common_item_class=LightKeyword,common_contributor=JavaCompletionContributor,ngram_recent_files=0.05531536291055828], ml_rank=5.605883358704432, before_rerank_order=2
showFocusedBrowserSearchToolbar	frozen=true, sorter=1, stats=0, explicitProximity=1, proximity=[accessibility=NORMAL, referenceList=unknown, samePsiMember=2, explicitlyImported=DECLARED_IN_SAME_FILE, javaInheritance=false, groovyReferenceListWeigher=unknown, openedInEditor=true, sameDirectory=true, sameLogicalRoot=true, sameModule=2, kotlin.preferKotlinx=null, knownElement=0, inResolveScope=true, directoryType=3, sdkOrLibrary=false], ml_weigh=[java_is_public=1,java_is_static=1,java_args_count=0.0,java_args_vars_names_matches=0.0,java_args_vars_types_matches=0.0,java_args_vars_names_types_matches=0.0,java_return_type=VOID,common_lines_diff=12.0,common_item_class=PsiMethodImpl,common_contributor=JavaCompletionContributor,ngram_file=5.420054200542006E-4,ngram_file_reversed=5.420054200542006E-4,common_similarity_parent_mean=0.7,common_similarity_parent_max=1.0,common_similarity_parent_full=1.0,common_similarity_parent_stemmed_mean=0.7,common_similarity_parent_stemmed_max=1.0,recent_places_contains=1], ml_rank=5.0996414910037515, before_rerank_order=0
short	frozen=true, sorter=1, stats=0, explicitProximity=0, proximity=[accessibility=NORMAL, referenceList=unknown, samePsiMember=0, explicitlyImported=UNKNOWN, javaInheritance=false, groovyReferenceListWeigher=unknown, openedInEditor=false, sameDirectory=false, sameLogicalRoot=false, sameModule=0, kotlin.preferKotlinx=null, knownElement=0, inResolveScope=false, directoryType=0, sdkOrLibrary=false], ml_weigh=[common_item_class=LightKeyword,common_contributor=JavaCompletionContributor], ml_rank=3.7346703738285214, before_rerank_order=1
switch	frozen=true, sorter=1, stats=0, explicitProximity=0, proximity=[accessibility=NORMAL, referenceList=unknown, samePsiMember=0, explicitlyImported=UNKNOWN, javaInheritance=false, groovyReferenceListWeigher=unknown, openedInEditor=false, sameDirectory=false, sameLogicalRoot=false, sameModule=0, kotlin.preferKotlinx=null, knownElement=0, inResolveScope=false, directoryType=0, sdkOrLibrary=false], ml_weigh=[java_keyword_name=switch,common_item_class=LightKeyword,common_contributor=JavaCompletionContributor], ml_rank=3.0984666223516797, before_rerank_order=3
synchronized	frozen=true, sorter=1, stats=0, explicitProximity=0, proximity=[accessibility=NORMAL, referenceList=unknown, samePsiMember=0, explicitlyImported=UNKNOWN, javaInheritance=false, groovyReferenceListWeigher=unknown, openedInEditor=false, sameDirectory=false, sameLogicalRoot=false, sameModule=0, kotlin.preferKotlinx=null, knownElement=0, inResolveScope=false, directoryType=0, sdkOrLibrary=false], ml_weigh=[common_item_class=LightKeyword,common_contributor=JavaCompletionContributor,ngram_recent_files=2.331517565102848E-4], ml_rank=3.0977302730744327, before_rerank_order=4
serr	frozen=false, sorter=2, stats=0, ml_weigh=[common_contributor=LiveTemplateCompletionContributor,template_previously_used=0,template_recent_use_count=0.0], ml_rank=2.36369747898857, before_rerank_order=5
souf	frozen=false, sorter=2, stats=0, ml_weigh=[common_contributor=LiveTemplateCompletionContributor,template_previously_used=0,template_recent_use_count=0.0], ml_rank=2.1653386836667323, before_rerank_order=6
sout	frozen=false, sorter=2, stats=0, ml_weigh=[common_contributor=LiveTemplateCompletionContributor,template_previously_used=0,template_recent_use_count=0.0], ml_rank=1.97021480944818, before_rerank_order=7
soutm	frozen=false, sorter=2, stats=0, ml_weigh=[common_contributor=LiveTemplateCompletionContributor,template_previously_used=0,template_recent_use_count=0.0], ml_rank=1.5190070933592779, before_rerank_order=8
soutp	frozen=false, sorter=2, stats=0, ml_weigh=[common_contributor=LiveTemplateCompletionContributor,template_previously_used=0,template_recent_use_count=0.0], ml_rank=1.5430891486746532, before_rerank_order=9
soutv	frozen=false, sorter=2, stats=0, ml_weigh=[common_contributor=LiveTemplateCompletionContributor,template_previously_used=0,template_recent_use_count=0.0], ml_rank=1.480286468696022, before_rerank_order=10