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Data Mining-based Tools to Support Library Update. PhD Defence of Oleksandr ZAITSEV

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Oleksandr Zaitsev

The document presents a PhD thesis defense focused on tools supporting library updates in software development. It emphasizes the common challenges developers face during library updates and proposes two automated tools: DepreWriter for on-the-fly method rewritings and DepMiner for inferring transformation rules from commit history. The thesis also discusses a developer survey to understand practices around library updating and highlights the need for improved documentation and tool support.

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Data Mining-based Tools to Support Library Update Oleksandr ZAITSEV PhD Thesis Defence Composition of the jury: Reviewers: Olga KOUCHNARENKO Examiner: Romain ROBBES Coen DE ROOVER Stéphane DUCASSE Nicolas ANQUETIL Supervisors: Arnaud THIEFAINE Co-supervisor:
2 (software company) (research institute) Advisor: Arnaud THIEFAINE Supervisors: Stéphane DUCASSE Nicolas ANQUETIL Paris Lille Cifre PhD
3 Arolla is a consulting company specialised in the advanced techniques of software development: Clean Code, TDD, BDD, Legacy Remediation, etc. https://www.arolla.fr/
Introduction Part 1:
5 Library Update Problem Client System Library v1.0 Client Developer Library Developer depends Part 1 / 6
6 Client System Library v1.0 Library v2.0 Client Developer Library Developer depends Library Evolution Library Update Problem Part 1 / 6
7 Client System Library v1.0 Library v2.0 Client Developer Library Developer depends Library Evolution ! Errors! Library Update Problem Part 1 / 6
8 Updated Client System Client System Library v1.0 Library v2.0 Client Developer Library Developer depends Library Evolution Library Update Library Update Problem Part 1 / 6
9 How to change client code to use the new version of a library? Supporting developers during library update by building tools My thesis is about: Library update problem: Scope of my Thesis Part 1 / 6
10 How to use the new version of the same library? How to use a different (although similar) library? Library Update Disambiguation Library Migration v1.0 v2.0 A B (e.g., update Struts v1.0 to Struts v1.2) (e.g., replace EasyMock with Mockito) Part 1 / 6
11 Motivating Example from ailib.models import LinearRegression from ailib.data import readData data = readData(‘dataset.csv’, type=‘CSV’) model = LinearRegression() model.train(data, ycolumn=‘salary’) salary = model.predict([26, ‘female’]) ailib v1.0 Client Developer depends Part 1 / 6
12 Motivating Example from ailib.models import LinearRegression from ailib.data import readData data = readData(‘dataset.csv’, type=‘CSV’) model = LinearRegression() model.train(data, ycolumn=‘salary’) salary = model.predict([26, ‘female’]) ailib v2.0 Client Developer depends Part 1 / 6 ! Error: LinearRegression not found ! Error: readData() not found ! Error: wrong argument passed to predict() ?
13 Motivating Example ailib v2.0 Client Developer depends Part 1 / 6 1. Rename LinearRegression to AILinearRegression 2. Replace readData(file, type) with readCsv(data) 3. predict() should now accept a list of rows instead of a single row Library Developer from ailib.models import AILinearRegression from ailib.data import readCsv data = readCsv(‘dataset.csv’) model = AILinearRegression() model.train(data, ycolumn=‘salary’) salary = model.predict([[26, ‘female’]]) communicate
14 Understand library update in practice: ‣ What problems do developers face? ‣ What support do they need? Propose a language to express code transformations Automatic transformations discovery 3 Aspects of the Problem Empirical Language Automation Part 1 / 6
15 Pharo is a pure object-oriented dynamically-typed programming language. We focus on Pharo because: 1. We have access to its core developers 2. Pharo is convenient for manipulating source code Pharo Programming Language Part 1 / 6
1. Introduction 2. State of the Art 3. Developer Survey of Library Update 4. Deprewriter: Smart deprecation rewriting 5. DepMiner: Recommending transformation rules 6. Conclusion Plan
State of the Art Part 2:
18 Technique Perspective Client developer Library developer Both Developer survey Code analysis Empirical Studies Part 2 / 6
19 Paper Survey Code Analysis Client Dev. Library Dev. [Robbes 2012a] X ✓ ✓ X [Jezek 2015] X ✓ ✓ ✓ [Hora 2015] X ✓ ✓ X [Bogart 2016] ✓ X ✓ ✓ [Sawant 2016] X ✓ ✓ X [Xavier 2017a] X ✓ ✓ ✓ [Xavier 2017b] ✓ X X ✓ [Hora 2018] X ✓ ✓ X [Kula 2018a] ✓ ✓ ✓ X [Kula 2018b] X ✓ X ✓ [Brito 2019] ✓ X ✓ ✓ Empirical Studies Part 2 / 6
20 Shortcomings: 1. Most surveys analyse specific cases of breaking changes. 2. No survey has asked client developers about what makes library update hard and what makes it easy. Empirical Studies Part 2 / 6
21 Problem Perspective Client developer Library developer Both Library update Library migration v1.0 v2.0 A B Tools to Support Library Update Part 2 / 6
22 Sources of Information Technique exp — developer expertise doc — documentation hist — commit history 2v — two versions of source code TS — textual similarity SS — structural similarity CD — call dependency Tools to Support Library Update Part 2 / 6 L — library C — already updated clients T — unit tests
23 Paper Update Library dev. Source Technique Dynamic Rewriting [Chow 1996] ✓ ✓ exp(L) — X [Henkel 2005] ✓ ✓ exp(L) — X [Kim 2007] ✓ — 2v(L) TS X [Xing 2007] ✓ X 2v(L) SS, TS X [Dagenais 2008] ✓ X hist(L) CD X [Schäfer 2008] ✓ X 2v(C,T) CD X [Wu 2010] ✓ X 2v(L) CD, TS X [Nguyen 2010] ✓ X 2v(L,C,T) CD, TS, SS X [Meng 2012] ✓ X hist(L) CD X [Teyton 2013] X X hist(L) CD X [Hora 2014] ✓ X hist(L) CD ✓ [Pandita 2015] X X 2v(L) TS X [Alrubaye 2019] X X hist(C), doc(L) CD, TS X [Alrubaye 2020] X X doc(L) CD, TS X Tools to Support Library Update Part 2 / 6
24 Shortcomings: 1. No studies propose automated tools to support library developers. 2. Most studies do not consider dynamic rewriting 3. Most studies focus on statically-typed programming languages. Tools to Support Library Update Part 2 / 6
(empirical aspect) Developer Survey Part 3: O. Zaitsev, S. Ducasse, N. Anquetil, and A. Thiefaine. How Libraries Evolve: A Survey of Two Industrial Companies and an Open-Source Community. APSEC (industrial track), 2022.
26 Updated Client System Client System Library v1.0 Library v2.0 Client Developer Library Developer depends Understanding the Developers Part 3 / 6
27 Updated Client System Client System Library v1.0 Library v2.0 Client Developer Library Developer depends ‣ How do they behave in the context of library update? ‣ What problems do they face? ‣ What support do they need? Understanding the Developers Part 3 / 6
28 Open-Source Industry Library developers 11 5 Client Developers 22 9 We selected developers from diverse communities for our survey Developer Population Part 3 / 6
29 Three times a year or more often Twice a year Once a year Less often We do not do it regularly Q: How often do they face the problem of library update? Selected Findings 17 10 3 3 3 Part 3 / 6 Client Developers
30 Q: What makes library update easy? Q: What makes it hard? Selected Findings Part 3 / 6 Factor dev. Documentation 15 Absence of breaking changes 11 Test coverage 6 Tool support 5 Deprecations 4 Simple breaking changes 4 Community support 3 Factor dev. Breaking changes 11 Absent or bad documentation 10 Indirect dependencies 7 Big changes to the API 7 Poor test coverage 4 Removed functionality 3 Changed hooks or abs. classes 3 Client Developers
31 Very small impact Small impact Moderate impact Big impact Very big impact Q: What is the impact of breaking changes on their clients? Selected Findings 1 0 9 6 2 Part 3 / 6 Library Developers
32 Q: Is it important for library developers to encourage their clients to update? Selected Findings Not important at all Of little importance Of average importance Very important Absolutely essential 0 1 5 8 4 Part 3 / 6 Library Developers
33 Library Developers Client Developers ‣ Often have to deal with the problem of library update ‣ Need documentation and support for breaking changes ‣ Want to help their clients to update Survey Conclusion Part 3 / 6
(language aspect) Deprewriter. On-the-fly rewriting method deprecations Part 4: S. Ducasse, G. Polito, O. Zaitsev, M. Denker, and P. Tesone. Deprewriter: On the fly rewriting method deprecations. JOT, 2021.
35 Deprecation Deprecation message Method Deprecations in Pharo isSpecial self deprecated: ‘Renamed to #needsFullDefinition’. ^ self needsFullDefinition Part 4 / 6
36 Deprecation Deprecation message Transformation rule Rewriting Deprecations isSpecial self deprecated: ‘Renamed to #needsFullDefinition’ transformWith: ‘`@receiver isSpecial’ -> ’`@receiver needsFullDefinition’. ^ self needsFullDefinition Part 4 / 6
37 isSpecial self deprecated: ‘Renamed to #needsFullDefinition’ transformWith: ‘`@receiver isSpecial’ -> ’`@receiver needsFullDefinition’ ^ self needsFullDefinition Antecedent (left hand side) matches the method calls that should be replaced Consequent (right hand side) de fi nes the replacement Transformation Rule Part 4 / 6
38 ‘@receiver whenSelectionIndexChanged: ‘@argument Expressing Complex Rules Part 4 / 6 ‘@receiver selection whenChangedDo: [ :selection | ‘@argument value: selection selectedIndex ] Antecedent: Consequent:
39 method “do something” method self deprecated: ‘Explain why’ transformWith: ‘`@rec method’ -> ‘`@rec newMethod’. Library Developer x.method() x.newMethod() “do something” ! Client Developer Step 1 Step 2 Step 3 Step 4 Step 5 Client code is rewritten Execution continues Rewriting in Action Part 4 / 6
40 Pharo 41 % 59 % Rewriting deprecations (contain a transformation rule) Non-rewriting deprecations (no transformation rule) Analysis of Deprecations in Pharo 8 (367) Part 4 / 6
41 Pharo 9 % 32 % 59 % Rewriting deprecations (contain a transformation rule) Non-rewriting deprecations (no transformation rule) Obvious opportunity Analysis of Deprecations in Pharo 8 (367) Part 4 / 6
42 Java 33 % 67 % Deprecations with helpful replacement messages Deprecations without helpful replacement messages C# 22 % 78 % JS 33 % 67 % [Brito et al., 2018] [Brito et al., 2018] [Nascimento et al., 2020] Replacement Messages Part 4 / 6
43 Deprewriter Summary Part 4 / 6 ✓ First documentation of Deprewriter approach ✓ Validity criteria for the transformation rules (detected 8 invalid rules in Pharo — merged PR) ✓ Analysis and discussion of non-rewriting deprecations in Pharo 8 ✓ Survey of developers who use Deprewriter Contributions:
(automation aspect) DepMiner: Inferring rules from the commit history Part 5: O. Zaitsev, S. Ducasse, N. Anquetil, and A. Thiefaine. DepMiner: Automatic Recommendation of Transformation Rules for Method Deprecation. ICSR, 2022.
45 The Need for Automation Deprewriter Library Developer Client System rules update Part 5 / 6
46 The Need for Automation Deprewriter Library Developer Client System update Tool Commit History rules Part 5 / 6
47 Missing methods — public methods that were present in the old version and no longer exist in the new version. new API old API Step 1. Detect Breaking Changes Part 5 / 6
48 Step 1. Detect Breaking Changes Part 5 / 6 Absence of method visibility. De fi ne language-speci fi c heuristics. https://github.com/olekscode/VisibilityDeductor Challenge 1: How we address it:
49 { Id: ef4fdd35fb05e74aa12aad4d22a37e17a8d87b5b, Removed methods: […], Added methods: […], Modified methods: [ { Old source code: …, New source code: …, Removed method calls: [smartDescription], Added method calls: [description], }], Added classes: […], Removed classes: […], … } Line-based diffs High-level commits Which lines of code were added or removed? Which methods, classes, or packages were added, removed, or modified? Q: Q: Step 2. Data Representation Part 5 / 6
50 Customer 1: Customer 2: Customer 3: { bread, butter, avocado } { bread, butter, bananas } { bread, butter, milk, cereal } Customer 4: { bread, milk, cereal } Customer 5: { butter, milk, cereal } Transactions: Q1: What are the products that are frequently purchased together? Q2: What can we recommend to people who buy bread? (frequent itemsets) (association rules) Step 3. Market Basket Analysis Part 5 / 6
51 Customer 1: Customer 2: Customer 3: { bread, butter, avocado } { bread, butter, bananas } { bread, butter, milk, cereal } Customer 4: { bread, milk, cereal } Customer 5: { butter, milk, cereal } Transactions: Q1: What are the products that are frequently purchased together? Q2: What can we recommend to people who buy bread? { bread } { butter } Con fi dence: 75% { bread, butter } { milk, cereal } Support: 60% Support: 60% Step 3. Market Basket Analysis Part 5 / 6
52 Q1: What are the operations that frequently appear together in method changes? Q2: What can we recommend as a replacement for next() ? { next } { nextNode } Con fi dence: 75% { remove(next), add(nextNode) } Support: 60% Part 5 / 6 Step 3. Market Basket Analysis
53 Node >> next self deprecated: ‘Use #nextNode instead.’ transformWith: ‘`@receiver next’ -> ’`@receiver nextNode’. ^ self nextNode Missing Method Node >> next Association Rule {next} {nextNode} Step 4. Generate Deprecations Part 5 / 6 generate
54 Step 4. Generate Deprecations Part 5 / 6 Absence of static type information. Retain only those association rules, where methods in antecedent and consequent of the rule are de fi ned in the same class. Challenge 2: How we address it:
55 Prototype Tool for Pharo Part 5 / 6
56 Famix 6,538 Moose 1,670 Pillar 5,848 Pharo 116,212 DataFrame 661 Tool Library SDK Project type: N Size (num. methods) Reviewers Selecting Projects Part 5 / 6
57 113 56 5 52 33 1 32 87 28 40 19 1 1 11 4 7 Pharo Famix DataFrame Accepted recommendations Rewriting Non-rewriting Rejected recommendations Moose Pillar Recommended Deprecations Part 5 / 6
58 Limitations of DepMiner Limitation 1 Limitation 2 Limitation 3 Simplified recommendations Unused / untested methods Naive search Developer may not want to deprecate. It’s correct but I will not deprecate Ineffective for methods that are not called internally test test test Coveragre: 80% v1.0 v2.0 breaking change effect Search entire commit history Part 5 / 6
Overcoming Limitation 1 Deprecation with a transformation rule Deprecation with a replacement message Deprecation without a replacement message Library update script with automatic rules Documentation with replacement message Documentation: list of breaking changes Does replacement exist? Is it automatable? yes no no yes Does developer want to deprecate? yes no Identified with the help of developers from Pharo open-source community 59 Part 5 / 6
Conclusion Part 6:
61 1. Developer survey to understand the practice of library update Contributions 2. First documentation of the Deprewriter approach. 3. Study of its adoption by the community 4. DepMiner — a novel approach to mine transformation rules. 5. Generalisation of DepMiner as a holistic approach. Empirical Language Automation Part 6 / 6
Future Work. Improve DepMiner 62 Limitation 1 Limitation 2 Limitation 3 Simplified recommendations Unused / untested methods Naive search Consider other actions of library developers (based on the table) Combine with existing approaches to detect refactoring. Detect commit that introduced BC Search neighbour commits Part 6 / 6
Future Work. Challenging Cases 63 1. Reassigning the existing name 2. Circular renaming 3. Modifying abstract hooks 4. Cleaning up spurious objects 5. String literals used as identifiers Method-to-method mapping: Part 6 / 6 Documented challenges: old API new API
64 2 Journal Papers ‣ N. Anquetil, J. Delplanque, S. Ducasse, O. Zaitsev, C. Fuhrman, and Y.-G. Guéhéneuc. What Do Developers Consider Magic literals? A Smalltalk Perspective. IST, 2022. ‣ S. Ducasse, G. Polito, O. Zaitsev, M. Denker, and P. Tesone. Deprewriter: On the fly rewriting method deprecations. JOT, 2021. 3 Conference Papers ‣ O. Zaitsev, S. Ducasse, N. Anquetil, and A. Thiefaine. How Libraries Evolve: A Survey of Two Industrial Companies and an Open-Source Community. APSEC (industrial track), 2022. ‣ O. Zaitsev, S. Ducasse, N. Anquetil, and A. Thiefaine. DepMiner: Automatic Recommendation of Transformation Rules for Method Deprecation. ICSR, 2022. ‣ O. Zaitsev, S. Ducasse, A. Bergel, and M. Eveillard. Suggesting Descriptive Method Names: An Exploratory Study of Two Machine Learning Approaches. QUATIC, 2020. + 2 Workshop Papers & 1 technical report 2nd best paper award at IWST’22 Best poster award at GDR GPL Publications (7 papers) Part 6 / 6
✓ Library update survey of developers. ✓ First documentation of Deprewriter ✓ Analysis of its adoption by the community. ✓ DepMiner — a novel approach to mine rules. ✓ DepMiner as holistic approach. Summary Contributions: Updated Client System Client System Library v1.0 Library v2.0 Client Developer Library Developer depends Library Update: DepMiner tool: 7 2 > 100 papers awards merged pull requests
Data Mining-based Tools to Support Library Update. PhD Defence of Oleksandr ZAITSEV
DepMiner Support A:
Static & Dynamic Analysis 68 Deprewriter Client System Commit History DepMiner Statically mine rules from history Dynamically apply rules to client code
Mining Method Call Replacements 69 Local subset of commits missing method m() history Method changes that remove a call to m() {remove(m), add(m’), add(x)} {remove(m), remove(n), add(m’)} … {remove(m), add(m’)} {remove(m), add(m’)} count: 15 {remove(m), remove(n), add(x)} count: 5 {m} → {m’} support: 15 confidence: 0.5 {m, n} → {x} support: 5 confidence: 0.3 A-Priori Transactions Frequent Itemsets Association Rules
70 public static LinkedList insert(LinkedList list, int data) { Node new_node = new Node(data); - new_node.setNext(null); + new_node.setNextNode(null); if (list.head() == null) { list.setHead(new_node); } else { Node last = list.head; - while (last.next() != null) { - last = last.next(); + while (last.nextNode() != null) { + last = last.nextNode(); } last.next = new_node; } return list; } Method change — one method modified by one commit Method Change Part 5 / 6
71 public static LinkedList insert(LinkedList list, int data) { Node new_node = new Node(data); - new_node.setNext(null); + new_node.setNextNode(null); if (list.head() == null) { list.setHead(new_node); } else { Node last = list.head; - while (last.next() != null) { - last = last.next(); + while (last.nextNode() != null) { + last = last.nextNode(); } last.next = new_node; } return list; } { remove(setNext), add(setNextNode), remove(next), remove(next), add(nextNode), add(nextNode) } Transaction — set of added and removed method calls in a method change: Method Change as Transaction Part 5 / 6
Challenging Problems of Library Update Support B:
Rewriting Abstract Hooks 73 FileReader read() Library v1.0 CSVFileReader read() Client
Rewriting Abstract Hooks 74 FileReader read() FileReader readFile() Library v2.0 Library v1.0 CSVFileReader read() CSVFileReader read() Client Client renamed Method is never called
Removing Spurious Objects 75 300 px 200 px 50 px offsets (a Rectangle) -71 46 120 px fractions (a Rectangle) 0.4 0.25
Removing Spurious Objects 76 300 px 200 px -71 46 bottomOffset rightOffset 0.4 0.25 bottomFraction rightFraction
Removing Spurious Objects 77 frame := LayoutFrame new topFraction: 0 offset: 0; leftFraction: 0 offset: 0; bottomFraction: 0.4 offset: 46; leftFraction: 0.25 offset: -71; yourself. fractionRectangle := 0@0 extent: 0.4@0.25. offsetRectangle := 0@0 extent: 46@(-71). frame := LayoutFrame fractions: fractionRectangle offsets: offsetRectange. v1.0 v2.0
Removing Spurious Objects 78 frame := LayoutFrame new topFraction: 0 offset: 0; leftFraction: 0 offset: 0; bottomFraction: 0.4 offset: 46; leftFraction: 0.25 offset: -71; yourself. fractionRectangle := 0@0 extent: 0.4@0.25. offsetRectangle := 0@0 extent: 46@(-71). frame := LayoutFrame fractions: fractionRectangle offsets: offsetRectange. v1.0 v2.0 We can rewrite method calls
Removing Spurious Objects 79 frame := LayoutFrame new topFraction: 0 offset: 0; leftFraction: 0 offset: 0; bottomFraction: 0.4 offset: 46; leftFraction: 0.25 offset: -71; yourself. fractionRectangle := 0@0 extent: 0.4@0.25. offsetRectangle := 0@0 extent: 46@(-71). frame := LayoutFrame fractions: fractionRectangle offsets: offsetRectange. v1.0 v2.0 Hard to find and remove
a b b c Library v1.0 Library v2.0 Problematic Renaming 80 a b b a Library v1.0 Library v2.0 Reassigning the Name Circular Renaming

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Data Mining-based Tools to Support Library Update. PhD Defence of Oleksandr ZAITSEV

  • 1. Data Mining-based Tools to Support Library Update Oleksandr ZAITSEV PhD Thesis Defence Composition of the jury: Reviewers: Olga KOUCHNARENKO Examiner: Romain ROBBES Coen DE ROOVER Stéphane DUCASSE Nicolas ANQUETIL Supervisors: Arnaud THIEFAINE Co-supervisor:
  • 2. 2 (software company) (research institute) Advisor: Arnaud THIEFAINE Supervisors: Stéphane DUCASSE Nicolas ANQUETIL Paris Lille Cifre PhD
  • 3. 3 Arolla is a consulting company specialised in the advanced techniques of software development: Clean Code, TDD, BDD, Legacy Remediation, etc. https://www.arolla.fr/
  • 9. 9 How to change client code to use the new version of a library? Supporting developers during library update by building tools My thesis is about: Library update problem: Scope of my Thesis Part 1 / 6
  • 10. 10 How to use the new version of the same library? How to use a different (although similar) library? Library Update Disambiguation Library Migration v1.0 v2.0 A B (e.g., update Struts v1.0 to Struts v1.2) (e.g., replace EasyMock with Mockito) Part 1 / 6
  • 11. 11 Motivating Example from ailib.models import LinearRegression from ailib.data import readData data = readData(‘dataset.csv’, type=‘CSV’) model = LinearRegression() model.train(data, ycolumn=‘salary’) salary = model.predict([26, ‘female’]) ailib v1.0 Client Developer depends Part 1 / 6
  • 12. 12 Motivating Example from ailib.models import LinearRegression from ailib.data import readData data = readData(‘dataset.csv’, type=‘CSV’) model = LinearRegression() model.train(data, ycolumn=‘salary’) salary = model.predict([26, ‘female’]) ailib v2.0 Client Developer depends Part 1 / 6 ! Error: LinearRegression not found ! Error: readData() not found ! Error: wrong argument passed to predict() ?
  • 13. 13 Motivating Example ailib v2.0 Client Developer depends Part 1 / 6 1. Rename LinearRegression to AILinearRegression 2. Replace readData(file, type) with readCsv(data) 3. predict() should now accept a list of rows instead of a single row Library Developer from ailib.models import AILinearRegression from ailib.data import readCsv data = readCsv(‘dataset.csv’) model = AILinearRegression() model.train(data, ycolumn=‘salary’) salary = model.predict([[26, ‘female’]]) communicate
  • 14. 14 Understand library update in practice: ‣ What problems do developers face? ‣ What support do they need? Propose a language to express code transformations Automatic transformations discovery 3 Aspects of the Problem Empirical Language Automation Part 1 / 6
  • 15. 15 Pharo is a pure object-oriented dynamically-typed programming language. We focus on Pharo because: 1. We have access to its core developers 2. Pharo is convenient for manipulating source code Pharo Programming Language Part 1 / 6
  • 16. 1. Introduction 2. State of the Art 3. Developer Survey of Library Update 4. Deprewriter: Smart deprecation rewriting 5. DepMiner: Recommending transformation rules 6. Conclusion Plan
  • 17. State of the Art Part 2:
  • 18. 18 Technique Perspective Client developer Library developer Both Developer survey Code analysis Empirical Studies Part 2 / 6
  • 19. 19 Paper Survey Code Analysis Client Dev. Library Dev. [Robbes 2012a] X ✓ ✓ X [Jezek 2015] X ✓ ✓ ✓ [Hora 2015] X ✓ ✓ X [Bogart 2016] ✓ X ✓ ✓ [Sawant 2016] X ✓ ✓ X [Xavier 2017a] X ✓ ✓ ✓ [Xavier 2017b] ✓ X X ✓ [Hora 2018] X ✓ ✓ X [Kula 2018a] ✓ ✓ ✓ X [Kula 2018b] X ✓ X ✓ [Brito 2019] ✓ X ✓ ✓ Empirical Studies Part 2 / 6
  • 20. 20 Shortcomings: 1. Most surveys analyse specific cases of breaking changes. 2. No survey has asked client developers about what makes library update hard and what makes it easy. Empirical Studies Part 2 / 6
  • 21. 21 Problem Perspective Client developer Library developer Both Library update Library migration v1.0 v2.0 A B Tools to Support Library Update Part 2 / 6
  • 22. 22 Sources of Information Technique exp — developer expertise doc — documentation hist — commit history 2v — two versions of source code TS — textual similarity SS — structural similarity CD — call dependency Tools to Support Library Update Part 2 / 6 L — library C — already updated clients T — unit tests
  • 23. 23 Paper Update Library dev. Source Technique Dynamic Rewriting [Chow 1996] ✓ ✓ exp(L) — X [Henkel 2005] ✓ ✓ exp(L) — X [Kim 2007] ✓ — 2v(L) TS X [Xing 2007] ✓ X 2v(L) SS, TS X [Dagenais 2008] ✓ X hist(L) CD X [Schäfer 2008] ✓ X 2v(C,T) CD X [Wu 2010] ✓ X 2v(L) CD, TS X [Nguyen 2010] ✓ X 2v(L,C,T) CD, TS, SS X [Meng 2012] ✓ X hist(L) CD X [Teyton 2013] X X hist(L) CD X [Hora 2014] ✓ X hist(L) CD ✓ [Pandita 2015] X X 2v(L) TS X [Alrubaye 2019] X X hist(C), doc(L) CD, TS X [Alrubaye 2020] X X doc(L) CD, TS X Tools to Support Library Update Part 2 / 6
  • 24. 24 Shortcomings: 1. No studies propose automated tools to support library developers. 2. Most studies do not consider dynamic rewriting 3. Most studies focus on statically-typed programming languages. Tools to Support Library Update Part 2 / 6
  • 25. (empirical aspect) Developer Survey Part 3: O. Zaitsev, S. Ducasse, N. Anquetil, and A. Thiefaine. How Libraries Evolve: A Survey of Two Industrial Companies and an Open-Source Community. APSEC (industrial track), 2022.
  • 27. 27 Updated Client System Client System Library v1.0 Library v2.0 Client Developer Library Developer depends ‣ How do they behave in the context of library update? ‣ What problems do they face? ‣ What support do they need? Understanding the Developers Part 3 / 6
  • 28. 28 Open-Source Industry Library developers 11 5 Client Developers 22 9 We selected developers from diverse communities for our survey Developer Population Part 3 / 6
  • 29. 29 Three times a year or more often Twice a year Once a year Less often We do not do it regularly Q: How often do they face the problem of library update? Selected Findings 17 10 3 3 3 Part 3 / 6 Client Developers
  • 30. 30 Q: What makes library update easy? Q: What makes it hard? Selected Findings Part 3 / 6 Factor dev. Documentation 15 Absence of breaking changes 11 Test coverage 6 Tool support 5 Deprecations 4 Simple breaking changes 4 Community support 3 Factor dev. Breaking changes 11 Absent or bad documentation 10 Indirect dependencies 7 Big changes to the API 7 Poor test coverage 4 Removed functionality 3 Changed hooks or abs. classes 3 Client Developers
  • 31. 31 Very small impact Small impact Moderate impact Big impact Very big impact Q: What is the impact of breaking changes on their clients? Selected Findings 1 0 9 6 2 Part 3 / 6 Library Developers
  • 32. 32 Q: Is it important for library developers to encourage their clients to update? Selected Findings Not important at all Of little importance Of average importance Very important Absolutely essential 0 1 5 8 4 Part 3 / 6 Library Developers
  • 33. 33 Library Developers Client Developers ‣ Often have to deal with the problem of library update ‣ Need documentation and support for breaking changes ‣ Want to help their clients to update Survey Conclusion Part 3 / 6
  • 34. (language aspect) Deprewriter. On-the-fly rewriting method deprecations Part 4: S. Ducasse, G. Polito, O. Zaitsev, M. Denker, and P. Tesone. Deprewriter: On the fly rewriting method deprecations. JOT, 2021.
  • 35. 35 Deprecation Deprecation message Method Deprecations in Pharo isSpecial self deprecated: ‘Renamed to #needsFullDefinition’. ^ self needsFullDefinition Part 4 / 6
  • 36. 36 Deprecation Deprecation message Transformation rule Rewriting Deprecations isSpecial self deprecated: ‘Renamed to #needsFullDefinition’ transformWith: ‘`@receiver isSpecial’ -> ’`@receiver needsFullDefinition’. ^ self needsFullDefinition Part 4 / 6
  • 37. 37 isSpecial self deprecated: ‘Renamed to #needsFullDefinition’ transformWith: ‘`@receiver isSpecial’ -> ’`@receiver needsFullDefinition’ ^ self needsFullDefinition Antecedent (left hand side) matches the method calls that should be replaced Consequent (right hand side) de fi nes the replacement Transformation Rule Part 4 / 6
  • 38. 38 ‘@receiver whenSelectionIndexChanged: ‘@argument Expressing Complex Rules Part 4 / 6 ‘@receiver selection whenChangedDo: [ :selection | ‘@argument value: selection selectedIndex ] Antecedent: Consequent:
  • 39. 39 method “do something” method self deprecated: ‘Explain why’ transformWith: ‘`@rec method’ -> ‘`@rec newMethod’. Library Developer x.method() x.newMethod() “do something” ! Client Developer Step 1 Step 2 Step 3 Step 4 Step 5 Client code is rewritten Execution continues Rewriting in Action Part 4 / 6
  • 40. 40 Pharo 41 % 59 % Rewriting deprecations (contain a transformation rule) Non-rewriting deprecations (no transformation rule) Analysis of Deprecations in Pharo 8 (367) Part 4 / 6
  • 41. 41 Pharo 9 % 32 % 59 % Rewriting deprecations (contain a transformation rule) Non-rewriting deprecations (no transformation rule) Obvious opportunity Analysis of Deprecations in Pharo 8 (367) Part 4 / 6
  • 42. 42 Java 33 % 67 % Deprecations with helpful replacement messages Deprecations without helpful replacement messages C# 22 % 78 % JS 33 % 67 % [Brito et al., 2018] [Brito et al., 2018] [Nascimento et al., 2020] Replacement Messages Part 4 / 6
  • 43. 43 Deprewriter Summary Part 4 / 6 ✓ First documentation of Deprewriter approach ✓ Validity criteria for the transformation rules (detected 8 invalid rules in Pharo — merged PR) ✓ Analysis and discussion of non-rewriting deprecations in Pharo 8 ✓ Survey of developers who use Deprewriter Contributions:
  • 44. (automation aspect) DepMiner: Inferring rules from the commit history Part 5: O. Zaitsev, S. Ducasse, N. Anquetil, and A. Thiefaine. DepMiner: Automatic Recommendation of Transformation Rules for Method Deprecation. ICSR, 2022.
  • 45. 45 The Need for Automation Deprewriter Library Developer Client System rules update Part 5 / 6
  • 46. 46 The Need for Automation Deprewriter Library Developer Client System update Tool Commit History rules Part 5 / 6
  • 47. 47 Missing methods — public methods that were present in the old version and no longer exist in the new version. new API old API Step 1. Detect Breaking Changes Part 5 / 6
  • 48. 48 Step 1. Detect Breaking Changes Part 5 / 6 Absence of method visibility. De fi ne language-speci fi c heuristics. https://github.com/olekscode/VisibilityDeductor Challenge 1: How we address it:
  • 49. 49 { Id: ef4fdd35fb05e74aa12aad4d22a37e17a8d87b5b, Removed methods: […], Added methods: […], Modified methods: [ { Old source code: …, New source code: …, Removed method calls: [smartDescription], Added method calls: [description], }], Added classes: […], Removed classes: […], … } Line-based diffs High-level commits Which lines of code were added or removed? Which methods, classes, or packages were added, removed, or modified? Q: Q: Step 2. Data Representation Part 5 / 6
  • 50. 50 Customer 1: Customer 2: Customer 3: { bread, butter, avocado } { bread, butter, bananas } { bread, butter, milk, cereal } Customer 4: { bread, milk, cereal } Customer 5: { butter, milk, cereal } Transactions: Q1: What are the products that are frequently purchased together? Q2: What can we recommend to people who buy bread? (frequent itemsets) (association rules) Step 3. Market Basket Analysis Part 5 / 6
  • 51. 51 Customer 1: Customer 2: Customer 3: { bread, butter, avocado } { bread, butter, bananas } { bread, butter, milk, cereal } Customer 4: { bread, milk, cereal } Customer 5: { butter, milk, cereal } Transactions: Q1: What are the products that are frequently purchased together? Q2: What can we recommend to people who buy bread? { bread } { butter } Con fi dence: 75% { bread, butter } { milk, cereal } Support: 60% Support: 60% Step 3. Market Basket Analysis Part 5 / 6
  • 52. 52 Q1: What are the operations that frequently appear together in method changes? Q2: What can we recommend as a replacement for next() ? { next } { nextNode } Con fi dence: 75% { remove(next), add(nextNode) } Support: 60% Part 5 / 6 Step 3. Market Basket Analysis
  • 53. 53 Node >> next self deprecated: ‘Use #nextNode instead.’ transformWith: ‘`@receiver next’ -> ’`@receiver nextNode’. ^ self nextNode Missing Method Node >> next Association Rule {next} {nextNode} Step 4. Generate Deprecations Part 5 / 6 generate
  • 54. 54 Step 4. Generate Deprecations Part 5 / 6 Absence of static type information. Retain only those association rules, where methods in antecedent and consequent of the rule are de fi ned in the same class. Challenge 2: How we address it:
  • 55. 55 Prototype Tool for Pharo Part 5 / 6
  • 57. 57 113 56 5 52 33 1 32 87 28 40 19 1 1 11 4 7 Pharo Famix DataFrame Accepted recommendations Rewriting Non-rewriting Rejected recommendations Moose Pillar Recommended Deprecations Part 5 / 6
  • 58. 58 Limitations of DepMiner Limitation 1 Limitation 2 Limitation 3 Simplified recommendations Unused / untested methods Naive search Developer may not want to deprecate. It’s correct but I will not deprecate Ineffective for methods that are not called internally test test test Coveragre: 80% v1.0 v2.0 breaking change effect Search entire commit history Part 5 / 6
  • 59. Overcoming Limitation 1 Deprecation with a transformation rule Deprecation with a replacement message Deprecation without a replacement message Library update script with automatic rules Documentation with replacement message Documentation: list of breaking changes Does replacement exist? Is it automatable? yes no no yes Does developer want to deprecate? yes no Identified with the help of developers from Pharo open-source community 59 Part 5 / 6
  • 61. 61 1. Developer survey to understand the practice of library update Contributions 2. First documentation of the Deprewriter approach. 3. Study of its adoption by the community 4. DepMiner — a novel approach to mine transformation rules. 5. Generalisation of DepMiner as a holistic approach. Empirical Language Automation Part 6 / 6
  • 62. Future Work. Improve DepMiner 62 Limitation 1 Limitation 2 Limitation 3 Simplified recommendations Unused / untested methods Naive search Consider other actions of library developers (based on the table) Combine with existing approaches to detect refactoring. Detect commit that introduced BC Search neighbour commits Part 6 / 6
  • 63. Future Work. Challenging Cases 63 1. Reassigning the existing name 2. Circular renaming 3. Modifying abstract hooks 4. Cleaning up spurious objects 5. String literals used as identifiers Method-to-method mapping: Part 6 / 6 Documented challenges: old API new API
  • 64. 64 2 Journal Papers ‣ N. Anquetil, J. Delplanque, S. Ducasse, O. Zaitsev, C. Fuhrman, and Y.-G. Guéhéneuc. What Do Developers Consider Magic literals? A Smalltalk Perspective. IST, 2022. ‣ S. Ducasse, G. Polito, O. Zaitsev, M. Denker, and P. Tesone. Deprewriter: On the fly rewriting method deprecations. JOT, 2021. 3 Conference Papers ‣ O. Zaitsev, S. Ducasse, N. Anquetil, and A. Thiefaine. How Libraries Evolve: A Survey of Two Industrial Companies and an Open-Source Community. APSEC (industrial track), 2022. ‣ O. Zaitsev, S. Ducasse, N. Anquetil, and A. Thiefaine. DepMiner: Automatic Recommendation of Transformation Rules for Method Deprecation. ICSR, 2022. ‣ O. Zaitsev, S. Ducasse, A. Bergel, and M. Eveillard. Suggesting Descriptive Method Names: An Exploratory Study of Two Machine Learning Approaches. QUATIC, 2020. + 2 Workshop Papers & 1 technical report 2nd best paper award at IWST’22 Best poster award at GDR GPL Publications (7 papers) Part 6 / 6
  • 65. ✓ Library update survey of developers. ✓ First documentation of Deprewriter ✓ Analysis of its adoption by the community. ✓ DepMiner — a novel approach to mine rules. ✓ DepMiner as holistic approach. Summary Contributions: Updated Client System Client System Library v1.0 Library v2.0 Client Developer Library Developer depends Library Update: DepMiner tool: 7 2 > 100 papers awards merged pull requests
  • 68. Static & Dynamic Analysis 68 Deprewriter Client System Commit History DepMiner Statically mine rules from history Dynamically apply rules to client code
  • 69. Mining Method Call Replacements 69 Local subset of commits missing method m() history Method changes that remove a call to m() {remove(m), add(m’), add(x)} {remove(m), remove(n), add(m’)} … {remove(m), add(m’)} {remove(m), add(m’)} count: 15 {remove(m), remove(n), add(x)} count: 5 {m} → {m’} support: 15 confidence: 0.5 {m, n} → {x} support: 5 confidence: 0.3 A-Priori Transactions Frequent Itemsets Association Rules
  • 70. 70 public static LinkedList insert(LinkedList list, int data) { Node new_node = new Node(data); - new_node.setNext(null); + new_node.setNextNode(null); if (list.head() == null) { list.setHead(new_node); } else { Node last = list.head; - while (last.next() != null) { - last = last.next(); + while (last.nextNode() != null) { + last = last.nextNode(); } last.next = new_node; } return list; } Method change — one method modified by one commit Method Change Part 5 / 6
  • 71. 71 public static LinkedList insert(LinkedList list, int data) { Node new_node = new Node(data); - new_node.setNext(null); + new_node.setNextNode(null); if (list.head() == null) { list.setHead(new_node); } else { Node last = list.head; - while (last.next() != null) { - last = last.next(); + while (last.nextNode() != null) { + last = last.nextNode(); } last.next = new_node; } return list; } { remove(setNext), add(setNextNode), remove(next), remove(next), add(nextNode), add(nextNode) } Transaction — set of added and removed method calls in a method change: Method Change as Transaction Part 5 / 6
  • 72. Challenging Problems of Library Update Support B:
  • 73. Rewriting Abstract Hooks 73 FileReader read() Library v1.0 CSVFileReader read() Client
  • 74. Rewriting Abstract Hooks 74 FileReader read() FileReader readFile() Library v2.0 Library v1.0 CSVFileReader read() CSVFileReader read() Client Client renamed Method is never called
  • 75. Removing Spurious Objects 75 300 px 200 px 50 px offsets (a Rectangle) -71 46 120 px fractions (a Rectangle) 0.4 0.25
  • 76. Removing Spurious Objects 76 300 px 200 px -71 46 bottomOffset rightOffset 0.4 0.25 bottomFraction rightFraction
  • 77. Removing Spurious Objects 77 frame := LayoutFrame new topFraction: 0 offset: 0; leftFraction: 0 offset: 0; bottomFraction: 0.4 offset: 46; leftFraction: 0.25 offset: -71; yourself. fractionRectangle := 0@0 extent: 0.4@0.25. offsetRectangle := 0@0 extent: 46@(-71). frame := LayoutFrame fractions: fractionRectangle offsets: offsetRectange. v1.0 v2.0
  • 78. Removing Spurious Objects 78 frame := LayoutFrame new topFraction: 0 offset: 0; leftFraction: 0 offset: 0; bottomFraction: 0.4 offset: 46; leftFraction: 0.25 offset: -71; yourself. fractionRectangle := 0@0 extent: 0.4@0.25. offsetRectangle := 0@0 extent: 46@(-71). frame := LayoutFrame fractions: fractionRectangle offsets: offsetRectange. v1.0 v2.0 We can rewrite method calls
  • 79. Removing Spurious Objects 79 frame := LayoutFrame new topFraction: 0 offset: 0; leftFraction: 0 offset: 0; bottomFraction: 0.4 offset: 46; leftFraction: 0.25 offset: -71; yourself. fractionRectangle := 0@0 extent: 0.4@0.25. offsetRectangle := 0@0 extent: 46@(-71). frame := LayoutFrame fractions: fractionRectangle offsets: offsetRectange. v1.0 v2.0 Hard to find and remove
  • 80. a b b c Library v1.0 Library v2.0 Problematic Renaming 80 a b b a Library v1.0 Library v2.0 Reassigning the Name Circular Renaming